The Seattle museum is really amazing, i went last year. The tour guides at the museum are retired Boeing and military guys, they got a real kick out of my 14 year old's questions and knowledge of cold war era SAM systems (mostly from playin g DCS) haha.
When I visited in 2018, one of the guides was a retired astronaut. I completely failed to have a conversation with him as I was star-struck and barely managed to hold a door open for him without making a fool out of myself.
I second the fact that the M21 is awesome though.