Researcher - Old 1021xx here which the tables say is from '25, exhibits the tang radius of your second pix, but the border engraving is much tighter, similar to #1 pix. Just another data point for you, though I'm sure you've seen dozens (if not hundreds) of the things.
Thanks for the tip on the trigger. Could be just corrosion - I'll find out when I get time to crawl inside.
Update - I couldn't stand the suspense and had to tear into it while my interest is still high. It's very beefy and heavy duty as you guys know, but mine does exhibit some fairly extensive corrosion - especially (surprise) on the sears. The nose of the left sear needs a polish job and it should be fine.
This one is a 30" job and undoubtedly has seen much use as a waterfowler. It has been apart, but it would seem not recently. I'd almost recommend based on this that a regular disassembly and cleaning isn't a bad idea if the gun is used outside in the real world much at all. Better to take it part while you can still get it apart.
I think I'll leave more complex SxS guns to the pros.
