I know this has been covered before.....regarding the serial number. But!......firearms produced in 1968 and earlier DO NOT have to have a serial number. Many of the .22 rifles and single shot shotguns (and of course some of the "lunch box specials")....didn't have serial numbers. But, as is...
I've had a number of those, over the last 40 years. None rebuildable....until recently. I got 3 of the USAF M13's out of an estate collection. They need assembly....and fitting of parts off some old Model 12 revolvers. I think I got the parts kits from APEX Arms.
I have 3 of the S&W Model M13 USAF marked revolvers (with alloy cylinders) that need repair and assembly. Mainly the side plates need fitting on 2 of them....as well as all the internal parts on all 3. I have all the required spare parts. That are out of the M12 alloy frame models, of the same...