I think your picture is upside down. Inverting it, the bottom line seems to read: FN HP/GP
The last characters of the first line read as TN to me. Possibly an importer from Tennessee?
* Looking again, that top line seems to read:
[ XX KNOX TN ]with the first two characters unreadable to me. There is/was an importer in Knoxville, TN. I don’t recall the name right now.
After a quick google search, I believe the first characters are TGI for Tennessee Guns Inc.
The entire string reads:
TGI KNOX TN
FN HP/GP
Cheers,
Tim