[ Ref. Dave Clark in 230515 MMDigest ]

Dave, I see a couple of problems with the flap valves.

1) The area the leather seats against must be smoooooth, with no
finish on it. I see yours is not smoooooth and has a finish on it.

2) The leather has curled, which leads to leaking. Typically on a pump
like this that is used a lot and has to provide a lot of vacuum, the
leather is reinforced, sometimes by gluing bellows cloth on the outside.

3) The inside leather is also looking a bit curled, which may be an
issue, and as you mentioned it nearly fills the recess. Right now it's
just using the flexibility of the leather to seal; there is no spring
tension on it. I think you need to see an unrestored or correctly
restored unit to see how it should be done.

David Dewey