s&w 29-2 123x6 also has an E4 stamp on the crane

[Hooper]

I am looking at a 29-2 nickel with the E4 stamped below the 123x6
The E4 looks to be fairly new stamp compared to the 123x6

I am curious to what the E4 stamp is. I am not sure if the crane is original to the gun or not.
Is it a stamp that shows work done after original manufacture maybe.
Just curious, I may try to purchase it, looks to be in great condition, like mint.

 

[dlbleak]

‘Usually’ if the factory did any work on it, the stamp would be on the side of the grip frame. But, one thing about S&W’s consistency is that it’s inconsistent! Can you post pics?