I recently picked up a mould that I thought might be of interest to you guys. It is a Yankee mould that is a copy of Ray Thompson's Ideal 429244 HP. The HP channel had been blocked by installing a fixed plug, cleverly held in place using the HP pin keeper screw (see photos).
I took a piece of 1/4" mild steel round stock and turned a HP pin to fit the channel (.158"), cut it off even with the top of the forward driving band and gave it a 7 degree taper (crossfeed angle, making it a 14 degree included angle).
I copied Lyman's snap-ring keeper idea to hold the pin in place, and made a knob for the HP from a piece of scrap walnut (see photo). Tonight I'm going to fire up the lead pot and see how this mould casts!