This from the Baltimore Arms thread:
SR#5135 on the action and 3135 on the forend iron.

I have seen this anomaly more than once. I always think it is a replacement if on a commonly built gun.But sometimes I have to really stop and think of the times and what may have transpired.
With the small builders and those that had limited resources, it may not be so odd to use parts that were in the bin.
One of the most perplexing guns that I have come upon is a Lindner built T.M.Golcher. The serial number was 11XX and the fore end iron was 200 more or less than that number.
Was it a mis-stamp or simply put together from the parts that were available?
I am certain that Lindner would have never allowed it out of Suhl that way, but what happened in Phila, I can only imagine.
I have decided to not worry about it in the old and rare guns and just be thankful that the parts are all there and intact on a desirable part of my collection.
Of course, being the Scotsman that I am proud to be, I bargain like there is no tomorrow on such a gun. LOL
Best,
John


Humble member of the League of Extraodinary Gentlemen (LEG). Joined 14 March, 2006. Member #1.