I have a chance to pick up a few hides on the cheap. 18 marten, 12 mink, only issue is that they have been cased and dried but they are a year old. A few of the hides have some mold on them. Are they ruined? Thniking of getting them tanned for decorative purposes but don't want to waste $ on hides and tanning if they aren't any good. Any experience with this?