re: Guitarists, check out this old box

Some belly behind the bridge due to age is common and could/should be expected for that age, particularly in the Gulf South's high humidity. If action and intonation aren't significantly affected, no big deal, let it ride.

On the bridge gap, I wouldn't necessarily reset it for one small end gap on a bridge ear - it's the back length of the bridge where the cause for concern exists. Tell your buddy to just keep an eye on it and if the gap starts spreading, particularly to the back of the bridge, that's when you pursue the reset. A tech/luthier who knows what they're doing should be able to not only save the bridge and saddle but also preserve the footprint and finish around it, aka invisible repair.

Really, REALLY cool piece, I'm green with envy!