Glad we visited this little gem. It's small but I learned a lot and enjoyed our visit very much. We looked at, interacted with, and read everything and it took us about 30 minutes. It's located on a nice little strip in a nice little neighborhood too although everything was closed on Sunday.
They're open from 12-4 every Sunday and admission is free. I believe there's another opening time on a weekday but can't comment on that. They do take donations so bring cash to leave one, we weren't able to.