I had no idea Glock made OD models when I got mine...
After buying a G30 and finding it was one of the best handguns I had owned in forty years of shooting, I decided I wanted a 9mm for cheaper practice.
I had a Beretta 92FS, which I liked a lot...got it in a bargain trade which amounted to about $275 on my end.
I put a "want to trade for a Glock 17" ad on armslist and got a response fairly quickly.
When I met the individual, I was surprised to see an OD frame when he opened the box.
I did the trade, and couldn't be happier.