An update, in case anyone is interested.

I took the bow apart completely this afternoon to get a look at everything, and lube the limb bolts, which were a little reluctant to turn. I've not seen any other bow exactly like this one. The limb pockets were deep, fixed pockets. Limb pivots were half-round aluminum, meeting an "ovalish" slot in the pocket. I decided to put some foam into the pockets to see if it would cut the slight ringing sound the bow made. Got the cams in synch, and put 10 twists in the string to shorten the draw some. Probably put the cams in less than ideal position, but it feels better to me now. This powerhouse is very quiet. Nice shooting qualities, no vibration at all, just a little recoil or forward jump. It is now much quieter than the Patriot Dually, Darton Rampage, and a few other more modern bows I've had. Probably on par with the Newberry B1 for noise. Pretty good for an old timer. Looking forward to shooting it through the chronograph to see what is really going on. Have to get over to the range and see how that 5 3/4" brace affects the accuracy (with a hack like me shooting it).