Strange Markings on Model 8 Receiver

[DWalt]

While just putting the final touches on my new-to-me Model 8, I noticed for the first time some odd markings just forward of the serial number stamped on the bottom of the receiver, to wit:



Best way to describe them is like two pairs of handcuffs separated by a backwards flat-topped crescent. They do not appear to be like any alphanumeric characters I have seen. Can anyone decipher the meaning? Or even seen similar stampings?

My crude drawing is not to scale. The lower SN is considerably larger in relation to the size of the symbol stampings, and also the top SN on th barrel flange, which is quite small.

[81police]

although I can't recall seeing markings just like those Dwalt, John Henwood describes all sorts of odd ball assembler symbols: trefoils, three-leaf clovers, double-ended arrows, six-point stars, pine trees, maltese crosses, anchors, candlesticks, etc. I can only assume each assembler had his own unique stamp!

[DWalt]

I was originally thinking they may have represented some date code, but those are usually letters. These are not. Also, possibly they could be some inspection stamp markings. But three of them, co-located? As I have no other Model 8s for reference, I wondered if all Model 8s have similar multiple markings (not necessarily the same markings) in the same location.

[81police]

assembler/fitter stamps were put in that location on both 8's and 81's. I've never tried to document how many different stamps there are, but there's a bunch!

[DWalt]

Well, there are two more for the collection, if anyone is documenting them.