I was looking for info on proof marks on a revolver I just purchased, and found a couple of .PDF pages taken from
The Blue Book Of Gun Values...
https://store.bluebookinc.com/Home/Default.aspx
https://store.bluebookinc.com/Info/P...Proofmarks.pdf
This one is at PIA and seems to be somewhat older -
http://www.phoenixinvestmentarms.com...Proofmarks.pdf
Here's a screenshot of one example of which I am confused...[pic below]...
"since 1891" indicates that they started putting this proof on "parabellum pistols" starting in 1891...before there was a "Luger"...
So...just what is a "Parabellum Pistol"???