Model 66-2: markings explained?

[shinbone]

I've got two new-to-me Model 66-2's. I am trying to understand the markings on each gun. As I understand it, the serial and model numbers are stamped in the frame just below the barrel (2nd photo after the photo of each gun). But what about the number stamped into the crane? (3rd photo after the photo of each gun). I am especially curious about what looks to be over-stamps. TIA, and the guns are fresh off the range so please pardon the dirt.

Gun #1

Gun #2

--shinbone

 

[jughed440]

"S" is for Stainless

The other numbers should be stamped on the frame under the grips. That was done to keep the matching parts together. Can always tell if a crane had been swapped out if the #s don't match

 

[murphydog]

The longer one is an assembly number for the purpose as noted above. The shorter ones are fitter's or inspector's stamps of mysterious meaning .

 

[Kernel Crittenden]

The assembly number will be found on backside of the side plate as well.