eBay has a 2213a right now for $114, incl. shipping that is "tested and functions correctly," a 2235 that passed basic tests with.a square wave for $185 shipped, and another 2213 that is "guaranteed to work" currently going for $20 plus $40 for shipping.
My reading tells me the 2213 is a better scope from a quality standpoint (made in the US), so I'll watch that auction and make a bid near the end if the price is in my budget. I could stretch a bit for the 2235 as well, so that's my 2nd choice.
I'm going to drop by the museum again and ask their advice on these models.
I'll post back when I've made a decision.
Thanks for all the input.