Respectfully, a dedicated .22 and a Glock conversion are not the same thing.
If you want to shoot a .22 get a Ruger/Buckmark etc. (arguably more accurate and definitely cheaper.)
If you want more trigger time behind your Glock get a conversion kit.
(reason being same sight picture and trigger pull)
My Glock has a matching serial number stamped on the frame, slide and barrel.
My AA conversion kit has no visible serial number and did not require a PAL to purchase. (Although I haven't tried it, you could probably fire a bullet out of it without the frame.)
Also mine is on a fixed diet of Remington Goldens