No Gulbransen player piano, to my knowledge, used a #71 bleed. The
pouches are small, but not even primaries use that size. The Ampico
model B used a fixed #71 bleed in addition to the ball bleed, but that
was only to start the valve off it's inside seat.
I would suggest guessing at this if you don't have an original bleed,
and trying the #63 cups. If you then need a smaller hole (which you
won't), you can paint them with something that will fill in the bleed
hole and redrill, or which will resize the hole with a coating.
If you have an original bleed, use a jeweler's drill set, and find the
correct drill that just fits the hole.
When unsealed pouch leather is used, it's seepage exceeds the bleed.
In that case, the bleed is just there to even out the average bleed for
all valves. When sealed pouch leather is used, if rubber cement is the
sealant, it's usually too stiff, because rebuilders wrongly apply the
cement after the leather is mounted as a pouch! That's called "wrong!"
If you use rubber cement, you apply it to the entire area of the skin
that you intend to punch out, first.
Usually, nothing happens to bleeds in a player, except they get filled
with lint and dirt, sometimes. Brass bleeds do not wear out. So unless
the bleed cups were for some strange reason removed, there is no reason
to replace them. If you have a repetition problem, the problem is not