[lugerholsterrepair]

This appears to be of Bulgarian origin. The cut down would be normal for these holsters and not a GI cutaway. It is possible this holster is not a Luger holster. The magazine pouch does not have the cut out for the magazine pull on a Luger mag.
From the pretty good photo's I think it is all leather. On many period leather items, particularly small pieces, you can see a similar impression on the back. This is formed when the leather is fed into a leather splitter to make the leather thinner. The rollers on the machine that cuts the leather, splits it to a thinner thickness, has to grab one side in order to push it into the cutter blade. I suspect this is the pattern on the surface leather made by the roller. Normally this is found on the suede side of the leather but this hide may have been mistakenly put into the splitter upside down. Jerry Burney