The bubbling shown in pic one would be typical of a ply drum and
the chocolate milk sealer would indicate a mid to late sixties vintage.
High humidity ( many Slingerland marching drums from this period
seemed to suffer this affliction ) was usually the cause in my
experience.
I've played outdoor gigs in the midwest summer where after sun set
the drum would actually fill with condensation.
Still, in this case dumpster diving has paid off...
:2Cents:
