I'm ok with that. Solves the mystery for me. Thank you.

I would imagine that in much of Europe, were you to wish to purchase a firearm where those numbers did not match, it would need be resubmitted for proofing with the two required shots of suchlike the Birmingham proofhouse, only to take possession of said gun. Of course, in the UK, that will not happen for most folk, so a moot point today, where formerly reading of such was common.

I have a German WW II that my Uncle got off a dead German in France, and there are SN's on the knife and sheath. Interesting.

Pap

Those are proof marks to show it has been fired with a proof deer....or proof of quality....or proof of tradition...or proof of insane obsession with numbering things and accountability/traceability....I vote the last one....in the US ARMY we call them rack numbers. I have seen many far newer knives numbered for components, including US made, whether folder of fixed.

Not sure if this makes sense or not?

http://www.thefirearmblog.com/blog/2018/02/21/brownells-glock-17-length-slides-for-glock-19-pistols/

If you have the money, and like playing Barbie with Glocks, ARs, 1911s, 10/22s, Ruger .22 Autos, etc, as those markets show bunches of folk do, the article lists the main points which are true.

It will cut down on recoil and muzzle flip, provide a longer sight radius, give a steadier hold, and it is the grip which pokes out in carry, and not so much the slide, unless the slide causes gun to rise higher in carry above the waistline.

Personally, bone stock is fine with me, as the guns only cost about $125 to make, and already highway robbery, and I see no point in throwing handfuls of money ignored by departing thieves and instead picked up by scavengers. And also my main feeling whether talking Colt and the 1911 and AR, or Glock, the makers know what makes their guns tick better than aftermarket folk, and a bunch of latest gotta haves have always turned out to be pure bunk or even problems after the new wore off.

But, other folk will see a fun way to tinker, and maybe end up with their ideal carry gun.

Took me a while to respond to your reply.
Yes to your point concerning cost. By the time you buy all the gazinta's to make up the slide, aftermarket barrel, and RSA, you're almost into the cost of a gun.

That's what I was thinking, Warren. If you want a 17, buy a 17. Granted the 19 has the compact grip, but how many carry a 17 concealed? A 19 is bigger than anything I want to carry and I'm pretty sure I can hit just as well with a 19 as I can with a 17 at "crisis" distance.

hey, long slides and short grips worked with Colt fans, so, somebody with time and money is gonna try. It does offer concealment and rapid hit potential gains for carry guys over a 17. Makes sense IF money is there. Do I expect Glock to copy the idea? Who knows with those guys. They know all and tell nothing. I am waiting for a longslide conversion for my 43 to come out!!!...or, maybe not...

In answer to Pat, I carry a 17 concealed, not much different than a 1911 in bulk, and 25% lighter loaded weights. But, with options, I generally opt for something else. Most never attempt carrying a 17 due to perceived enormous grip, which takes us back to the subject at hand. Personally, if I am carrying something as fat as a 17/19, will take the capacity, too.

Speaking of longslides, I remember the 7" AMT Longslide 1911. Never shot one but it looked wicked cool.