Sorry, can't comment on those museums.

We did take a hop on/off bus (near the main train station), and hopped off at the Atomium. It has some older exhibits inside. I'm not going to say it was the greatest thing in the world, but it was ok. Later on the tour we hopped off to go to an automobile museum, which was ok also.

Be sure to see the statue of the little boy, Manneken Pis. It's in a cute, touristy neighborhood, but very important to people of Brussels heritage.

http://en.wikipedia.org/wiki/Manneken_Pis

You might consider some day trips from Brussels. perhaps Antwerp? Haven't been there in a while, but heard it's a very good fashion destination lately. It's about a 45 min train ride, IIRC. If you are Jewish, there is a large population in Antwerp as it's the diamond capital of the world and lots of Jewish history as well.

http://www.sacred-destinations.com/belgium/antwerp-jewish-quarter.htm

http://www.planetware.com/tourist-attractions-/antwerp-antwerpen-anvers-b-a-aaa.htm

there are several museums at the Cinquantenaire (jubelpark in dutch). there's an art museum (which you wouldn't be interested in), a military museum, and Autoworld. I remember seeing a beer museum as well near Grand Place somewhere?

BTW: Leuven, Ghent, and Antwerp are easy day trips if you've had your fill of Brussels.

Not sure if it's non-artsy enough, but in Brussels you can also visit the Art Deco mansions of famous architects like Horta's house. The explanations are all also in English.
http://www.hortamuseum.be/

Or if you are more into politics:
http://www.europarl.europa.eu/visiting/en/parlamentarium.html

One museum geared more at the history of all of Belgium and not just Brussels:
www.belvue.be
Even if the exhibits don't interest you, you could pop in if you are in the area to have a lunch or snack in the nice courtyard/ patio.

The royal Botanical Garden in Laeken also comes to mind. Though it is a bit difficult to get there as it can only be reached by bus.

If you should make it to Antwerpen you would also find the Museum aan de Stroom there.
One or two of the ten floors are dedicated to art, but the "rest" is history of the city and port of Antwerpen and also other thematic exhibitions.
http://www.mas.be

As tailsock said, just because you stay in Brussels does not mean visiting the other towns was by any means a difficult task. Trains run 3-4 times/hr to Leuven, Gent or Antwerpen and don't cost much.

Thanks for the input so far. To explain further - we did plan to walk around Grand Place and look at the Manneken Pis. Also intend to take a day trip by train to Brugge which is supposed to be beautiful.

One day DH will be tied up with business and I wanted to do one of the chocolate tours as they include a workshop which wouldn't really interest him. (He wants to eat chocolate, not make it.) Anyone have experience with a good choice for this?

That leaves only two days together in Brussels - one of which will be our arrival day after an overnight flight. The hop-on hop-off bus might be a good idea then. While Antwerpen sounds interesting, don't think we want to do a second day trip.

Has anyone been to any of the museums I mentioned above or know of other non-art ones in Brussels that they would recommend?

I went to several of the museums you list and my French is 30 year old high school French so I also appreciate signs/explanations in English. The MIM (musical instruments) has all explanations in English plus there's a very good audio tour that lets you hear some of the more unusual instruments being played. THere's also a restaurant on the top floor of MIM with wonderful views and good food. The best thing in the Museum of the City of Brussels is their collection of all the 400+ outfits that have been provided for the Mannekin Pis statue to wear; the uniforms are displayed in cases on the top floor and are very intereesting (the clothing is there, along with a photo of the statue wearing the outfit. Very droll (unintentionally) and there's a funny video of people's reactions to the statue. I don't think the descriptions are in English but they're self-explanatory and your basic French will be fine for that. Also, for a fun souvenir, you can buy decks of playing cards of the statue wearing the outfits from the museum's front desk.

My favorite museum was the Royal Armed Forces and Military History Museum - it's huge, lots of mahogany cases filled with uniforms throughout the ages, weapons, flags, etc. Plus, military machinery. They had a special exhibit on the Belgian army's role in the Korean War and all those signs were in English also. The older displays (some of the costumes and weapons) didn't have English text but again, it was easy to figure out. Not crowded at all and very evocative.

I didn't do a chocolate tour but can highly recommend the chocolate from Passion!

I forgot to mention - like someone else suggested, I really enjoyed the Horta museum but you'd have to like architecture or Art Nouveau (all signs were in English too). I took a day trip to Ghent and loved it - there's a great castle (Gravensteen), a design museum, a Huis van Aljn (wrong spelling but it's old almshouses that were converted to a museum where each house is furnished to represent a certain era - goes up to the 1970's - very well done and fascinating.) Not to mention churches and lots more. I ran out of time in Ghent...

You mentioned the African museum in Tervuren - it's one of the old-style museums, a bit dusty. I thought it was OK, not great. However, the tram ride out there is considered one of the prettiest in Brussels. There used to be a website run by a local paper which had videos of the nicest tram rides and that one was voted the best. Unfortunately that link is now gone.
I would also give an honourable mention to the car museum in Cinquantenaire, which is a nice big park. Keep going to the Merode area, where there is a small shopping street and an opportunity for a coffee.

You might consider the museum in the Porte de Hal, which is one of the remaining fortifications of the city:
http://visitbrussels.be/bitc/BE_en/museum/2073/porte-de-hal-museum.do

Also even if you aren't an art fancier the Horta is very impressive. The architect Victor Horta created his own house in the Art Nouveau style. No detail was left out. All I can say is, he must have been a single man as there is even a pull-out urinal in the bedroom for him (which is not, by the way, the amazing thing about the property, it really is extremely beautiful):

http://www.hortamuseum.be/main.php?lang=en

And since you have a little bit of time you might visit the castle in Gaasbeek, which is on the outskirts of Brussels:

http://www.kasteelvangaasbeek.be/kasteel.asp

Don't forget to explore Ixelles - the area between Avenue Louise and Chaussée d'Ixelles - Chaussée de Wavre (Matongé) has lots of interesting shops and cafés, and is not touristy.

There is actually quite a lot to do in Brussels for the size of the city.

Lavandula