I am also interested in the pouch leather issue.  I just
replaced the bug eaten zephyr skin in my Pratt-Read with
pouch leather from the Player Piano Co.  I also just
purchased Bestine Paper Cement and Cement thinner (both
heptane based).  I was assured by the salesperson
that this was indeed "rubber cement".  I think she thought
that I took her for an idiot when I kept asking her if she
was sure that this is really rubber cement( after all, it
doesn't say rubber cement, does it?).  I usually say too
much, as I apparently did this time, and told her what
I was using it for and that I didn't expect to have to redo
the pouches for 50 years, so I want the right stuff.  She
thought I was crazy and said, "See you in fifty years!" as
I left.

I purchased it at Taw's stationary in Philadelphia.  I found
that most hardware stores and stationaries do not carry
the thinner.

I tested a 50/50 mixture on a pouch and it seems to
penetrate well and remains very flexible after drying.
The pouch now seems airtight.  Thanks to Les Smith for
his advice.

Larry Toto