It's a Brownie Target Six-20, made in 1946. I didn't know if it was operational when I bought it, although the shutter fired, so it was a delight to get it open when I got home (because Chris and I both had to find the manual online to see how to get the darn thing open) and see it looking like new.
We've already ordered some film for it, which is 620 size, not 35 mm (also takes 120 if you roll it onto the 620 spool), and comes in rolls of 8 exposures. Just 8!
I can't wait to learn how to use this little thing. It's already wonderful as a prop for 1910s-1940s costume events, but even better that I'll be able to take photos with it too. To me, that adds a whole new dimension to spending the day in vintage costume in an effort to connect with history :-).