I was recently contacted by a shul here in the Pacific Northwest about treating a problem with mold growth on two of their sifrei Torah. Having briefly looked through both sefarim it looks like the mold is fairly widespread manifesting in black spots along most of he margins and in a few places across areas of writing. Based on my recommendation the shul took immediate action to dramatically reduce the level of humidity within the shul which has been nearly 100% by installing de-humidifiers. The humidity is now holding at approximately 55%. At this level, I think mold growth is much less likely, but it still leaves the tricky issue of dealing with with what's already formed on the Torah scrolls themselves. I've done a bit of research on dealing with mold on parchment and it seems like there's quite a range of opinions, everything from misting the parchment with a solution of alcohol to exposing the klaf to direct sunlight for an hour, to using UV lamps.
Does anyone have any experience dealing with this type of issue successfully?