Have you tried just putting a bit of oil on it to soften the leather. Thats what I did on my A-34 (10ER) jigsaw See the maintenance section in the manual,
if you are making a new one, I believe the leather is formed while wet, but I have no experience on that
I have read of people just using an aquarium air pump instead, to get a better air stream. but again no personal experience.
10ER #23430, 10ER #84609, 10ER #94987,two SS A-34 jigsaws for 10ER.
1959 Mark 5 #356595 Greenie, SS Magna Jointer, SS planer, SS bandsaw, SS scroll saw (gray), DC3300,