Tom
Sorry for delay on response. I have pondered why mold suddenly started where there had been none for years. The only thing that comes to mind is a couple of holsters I have. One is a Black Walther PP ex-West Berlin Police,the other a Paki luger repro. I had them in a different location and noticed that the white stitching had a odd white powder on them.No sign of mold on the leather,just the stitching .So,I cleaned this off and tossed them in with the rest of the holsters.
Pretty sure that was the infection point.
Moral?
Check your very leather carefully. Esp. ones that have been sitting in surplus storage somewhere.
Bob