[lugerholsterrepair]

George, Mildew can be brushed away for the most part or wiped off. I use an old soft bristle tooth brush and a rag. If the holster is dry it should come right off. I have sometimes used a VERY little saddle soap, moist brush or rag. If the holsters are stored in moist conditions it will return.
Sometimes it is not mildew at all but gunk or oil someone has put on the holster at one time leeching out. In this case it will feel oily to the touch.
It's best to store holsters in dry dark conditions if possible.
A resource for holster marking is pretty broad. I have thousands of dollars invested in books so don't know where you might look on the net for a good reference. Maybe one of our more savvy internet members knows.
Actually basic holster markings are not at all complicated generally speaking. Untill you get to codes, GXY stuff like that, then you have to have a large book of codes and makers.
I am looking to find a Sauer 38H and an Italian 1934/5 Beretta holster, Artillery's Navy's etc. Damaged holsters, parts...anything like that. Let me know if you have anything for sale...Thanks, Jerry Burney