I took the bag to FSH. They were so nice, truly top notch service. The artisans said not to worry that the bag would likely improve about 80% as it continues to dry out and also that it is not noticeable. Although I can still see the water damage, it has definitely improved and you would never know if you weren’t looking for it, and even then only in certain light. So I am relieved! They said it’s very important even with Epsom to wipe any water off immediately (should be common sense I know - think I was in the rain too long and the bag was moist for like 30-60 min before I noticed). Lesson learned :/