Does anyone have any idea what the '125' means?

Length of the earstem.

Why would it be on one and not the other? I have several other color ways and the '125' is not in the ear stem?

No idea. Oakley went through a phase where they did stuff like that but now are using industry standards. For the Crankcase, it might be a mistake or just Oakley being Oakley with their earstem printing. There are also other pairs where Oakley didn't have any printing at all on a pair at first but changed that shortly after release. Oakley's odd that way,

Does the one with the 125 have the made in USA markings?

Yes, it does have the made in the USA marking on the opposite ear stem.

Then Oak's explanation is probably the best one you will get then.

I know there are some frames that will no longer be made in the USA so I thought maybe this was one of them. The switch to a different manufacturing facility could have explained the different printing.

Those Non- part number numbers are definitely in regards to size. The 56 is the Lens width, the 17 is the nose bride width and 125 is the Tempel width, all measurements are in milimeters.

Here at SGH we got some of the new JIP exclusives, and I noticed the white gascans no longer have the made in usa marking.