Thank you, all! The OP is very happy to have all the great input. I am going to sit now with all the new ideas and rethink the itinerary a bit. Toledo is an interesting idea for an add-in. And also looking into flying instead of train in at least one direction possibly at the end of the trip, right into Madrid and then out again to home. Will let you know where I land! Thanks so much!

If you do that, try to book on the same ticket as the flights into and out of Spain -- that way, if something goes wrong with the connection, it will be up to the airline(s) to make arrangements to get you to your next destination. If you book them separately, leave PLENTY of time just in case there is a problem, or be prepared to miss your flight home.