My foot made a cameo appearance for those of you into feet.
The setscrew for the eccentric bushing got a dab of blue loctite and was not overtightened. The bolt that clamps the casing around the eccentric bushing was very carefully torqued with the retainer plates correctly oriented after tensioning the belt. Initial tests found the quill bearing getting hot so I slackened the tension a little bit. Hopefully I found it's happy place. There isn't a lot of resistance in the drive train, but there is some. Spool-down when I turn the machine off is pretty quick with just the drill chuck attachment. Lubrication points were all oiled.
Still have to adjust the speed control which sent me into the deep dark abyss of that topic with all the charts and such. Wow it goes way deeper in depth than I will ever go. I'm going the route of adjusting the high speed stop as the manual tells me to do and measuring the belt against the outer edge of the sheaves 1/8'' to 1/16'' and calling it good. Plus there's a lathe sticker on the side of the headstock that says what rpm some of the letters are so it has to be right.

Russ, I took a picture of the straight gilmer gear w/out a clutch side by side with the clutched version showing the differences in the parts and the location of the setscrew you were mentioning before.
I don't normally do follow-ups very thoroughly but the great community of enthusiasts here made me want to do a little more. So cool that an old tool from the 1950's, parts that you can't buy anymore, is still running in 2023 thanks to all of you. Simply amazing.
I'd be curious how many years ago the gear I was looking for went out of production. All of this work will definitely be in my mind as I resume using the old guy for sure.
Thanks again to all,
Dan