Hi All,  I am reassembling my rebuilt Ampico A expression mechanisms
and need some advice.  As originally assembled on my piano, by
the factory, the springs on the push rods above the re-regulator
pneumatics are about 1/8 inch different in length from the stop
collar to the bottom of the expression box.

What should the correct length for the spring be and/or should it be
assembled with a certain amount of compression?  Since this spring
works against the re-regulator pneumatic, I expect that there should
be some standard reference so that the bass and treble work the same,
and so they work properly.  Your expert advice is appreciated!

Also thanks for all the responses to my question about Phenoseal.
I believe I will stick with shellac.

Pat DeWitt
phdewi@comcast.net