Eric,
This topic is covered in several books published on Lugers (Datig, Reese, Kenyon, Walter, etc). Read some of them and they will answer your questions to the extent that information about this scarce variation is known. To the best of my knowledge, there has been no positive identification of a holster that was unique to the Russian Lugers.
I thought I posted a photo of my Russian along with an ultra-rare Russian manual (I am not aware of any others), but I can't find it on the Forum, so here it is again.
