[DropTheE]

One of those shark steamer cleaner things might work to soften up the glue and then scrape it off with a razorblade.

Alot of travel humidors have foam insterts, perhaps if you were able to find a nice bed of solid foam and then use pick and pluck to make your cigar cradles. Sporting goods stores are pretty good about carrying pick and pluck in their gun departments.

If it is an anvil case, those are really good about keeping the water out anyway, I have had rain fall on my anvil cases and the inside stays dry. I don't see you leaving your cigars out in the rain very often. Great looking case, outside has some attitude. A great sign of any road case.