One of the problems Sam is having is the mixture of 50/50 rubber
cement.  This is far too thick, and who ever recommended a 50/50
mixture was in error.

Sealing leather pouches is very tricky and the rubber cement should be
very very thin, allowed to dry, and possibly a second coat.  The rubber
sealer should be invisible.  Then, dusted with pure talc.  (Not talcum
powder which contains starch, and could draw insects, or mildew.)

My suggestion is to gently try and remove the excess rubber cement
using naphtha, keeping in mind that it is highly flammable.  There will
be enough soaked into the leather to seal them.  Just dust them with
talc.  Then check for other problems.

Bruce Clark