Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

  Frank....I can just see the S/V in your photo.
How does it work?  What fits into the space between
the walls of the S/V body and the movable middle part? 
A custom shaped washer of some sort?  I just cobbled a
solution together that did not involve any mods.  If you
don't have any photos of one in pieces maybe you could
draw a diagram.

And, if you have a troublesome early 34 on your hands...

Eager to make it right,
Wayne