It's deja vu all over again----mainspring's a quarter inch short.
My 10" 1st Model shipped to Germany. It came back with an action to die for---and a vastly superior front sight.
"Ralph's Bath" is a procedure that was afforded to every S&W that ever came to live here. The gun comes all apart/soaks in Mineral Spirits for a spell---2-3 days (or longer)---every piece/nook/cranny/hole gets scrubbed to within an inch of its life---gets rinsed in clean Mineral Spirits, and blown dry with high pressure (125 psi) DRY air. Then it gets hosed down with CorrosionX, and left to sit for another spell, and blown as dry as it'll get; and then put back together---to then have the CorrosionX removed from the exterior with Hoppes #9, dried/polished, and put on the shelf. There were such guns on the shelf for 30+ years with no further attention other than a periodic dusting with a vacuum cleaner---a couple of times a year.
So, the 10" 1st Model is going back together---WHOOPS!! The mainspring is too short----won't reach the hammer. After some sitting and staring I notice another notch in the frame for the bottom of the mainspring---about a quarter inch above the notch S&W made for it. Then I compare the too short spring with what's supposed to be in the gun, and start to realize at least part of the reason the gun has an action to die for----its not only too short, it's also too thin---and too narrow. Hmmmmmmm?!!
Replacing the spring in the notch it came out of solves the problem---and all is well---but I never got a chance to talk to the folks who made the gun what it was---probably just as well, 'cause I don't speak German.
Ralph Tremaine