Good for you. I sure like my gen-1 23...


...and my new 35.

The 23 came with a operating-rod laser site, but I'll be removing that as soon as I can find an original rod and spring. Both have had a little 'finger-groove' enlarging (visible above) and feel much better than original. I don't have large hands, but this compact-frame model sure feels great with the Pierce Magazine extender.

Yeah!

Did the First Gen Glock have two different grip designs?
Because this is what I thought the Gen1 G17 looked like

This was the Gen2 design

Gen3

Gen3 RTF2

I think you both might actually have Gen2 guns.

My Serial is ZR, not Three Letters. Its my understanding that the 3 letters started the 2nd gen. Unless my receiver was upgraded at one point in time. But the serials match on the slide and barrel

Not trying to say it is not first gen. Just going by the looks of the guns they look second gen.

Cant find ZS in any Serial number index for Glock guns.

Any who. Hope you like your gun. If I could find a first gen g17 for a good price I would probably get one. Very happy with my 3rd gen.

Personally, I would like to know what I have as well. Ill call or email Glock tomorrow.

Closest thing I can find is here http://www.glocktalk.com/forums/showthread.php?t=412093

From the Glock Talk forum. When you get to the GT page start scrolling down and youll find them.

ZB - G-17 - January 1992
ZE - G-17 - January 1992
ZF - G-17 - February 1992
ZH - G-19 - January 1992
ZS - G-17 - - 2nd Gen.
ZU - G-22 - February 1992
ZX - G-23 - March 1992 -
ZZ - G-17 - - 2nd Gen. - Austrian, no polygon barrel (ordinary rifling)

I believe those are the only registered serials. Correct me if Im wrong

Could be thats all they are. I did a search for serial number designations for the Glock 17 and one of the returns was for that list at GT.

I realize that with the millions of Glocks made annually there could be any number of combinations. But looking at the list it seems that by the time the serial numbers have reached the Zs it looks like the Gen1 production has already stopped and they are all Gen2s.
Just an observation.
As there seems to be no definitive list on the SNs and the Gen1s are still produced well in to the Gen2s according to the list, it looks like your pistol may well be a Gen1.