thanks for the description and drawings TOYMACHINE, they look prety acurate to me. Since it does seem like a spool then this regulators may be suffering from sticking issues kind of like FSDO on spoolvalved guns. I have noticed that the internal finish on my thumper is not totaly smooth, jut a bit better than the outside dust finish.
Im thinking of doing a high polish on the internal walls and using higher durometer o-rings to see the effect on that reg. Anyone else tried something like this ??