[ithacaartist]

Dave, I'm sure others will give you more specific stuff, but I'll take a crack at getting you started. Blued, crimped construction, aluminum bottom. Somebody will know for sure if a serial number should be appearing on it; this one looks un-messed with to me nor ground/renumbered. I'm thinking late 30s, early 40s--before the FXO code style machined body, and after unmarked ones from earlier 30s? Nazi proofed, so WWII. $1-200?, +/- spring replacement.

Yes, the pin should push through without a lot of trouble--providing your setup will prevent deformation of the mag body when the pin is removed or installed. You need a hard, smooth surface below with a relief hole precisely beneath the pin, to support the sheet metal--and the proper punch. I compress the spring as much as possible in the mag body by hand, then hold it compressed with a needle-nose spring clamp wile installing or removing the pin. G.T. can hook you up with a replacement mag spring, and if you're careful, you should be able to install it in place of the oldie seamlessly, no harm, no foul.