Awesome sauce Warren, thanks a lot. Where else but this forum could somebody say "oh yeah, give me a few minutes to go look at my super rare, original and get a measurement for you."
Next I'll see if my generic Harbor Freight floor drill press has the gumption to sneak up on that diameter. I'm sure I'll end up pre-drilling with multiple smaller bits first.
I appreciate everybody's help.

Regards - Chris

Does anyone got drawing of smoke discharger bracket, please? Side view preferably, I need to get proper elevation of the discharger. Thanks :note: