I know people here will have their own suggestions, but I went through some similar discussions last yer. See:
http://graflex.org/helpboard/viewtopic.php?topic=2981&forum=15&15
I settled on a quick Lysol spray. Kills the mold and it hasn't returned for this past year. Humidity here ranges from 10% Winter through 95% Summer...
Now, if you've got real leather which is pretty rare, you have to take more precautions. Leather will withstand alcohol even in a good soaking. But it will dry out the oils tat keep it flexible and it may wash out the dyes that make it black/red or whatever. So for any leather goods, try a small patch, maybe with a q-tip first to see what happens. Any oils removed by solvents can be replaced with products suchh as neetfoots oil or evcen lemon Pledge (excellent for both leather and vinyl).
If you've got vinyl, don't worry about it and use Lysol, then lemon Pledge afterwards.
If you've got the time, patience, area and equipment, use the thymol fuming...