Back when I was discussing my woes with the Deleika 20/31 grind organ,
someone suggested that the white bellows leather was porous.  Since then
I've seen various substances recommended for sealing pouches; I'd assume
that in less dilute form these same items would seal bellows leather as
well.

Let's see: silicone caulk (a la bathroom tile caulk), RTV rubber
(probably harder to find), Sil-Glyde (not as airtight, and may render
the bellows boards impossible to glue to when recovering down the road),
and Neatsfoot Oil (keeps leather flexible but no value as sealant), rubber
cement (supposedly works but messy, and be sure to powder the baby's
behind :-), etc...

Way back in my player piano days PPCo sold Nu-Fab, a rubber-in-water
emulsion that I used temporarily on a piano reservoir till I got a chance
to rebuild them properly.  It sort of worked for a day or so.

Any suggestions?  I have the bellows out of the organ and can find no
actual leak or crack anywhere, and I know the leakage (about one pipe's
worth) is at the bellows end, not the chest.

Thanks, Mike Knudsen