Hey, Rex -
Those are x,y coordinates, the call outs are based on the center axis, and the plan is to enter those coordinates into a digital Bridgeport mill to accomplish the deed.
Fordboy has too much time and I've got too much money invested to not do it right.
Nevertheless, I do want a 1:1 drawing, which I think is doable, just as a check. I can use a Spridget backplate to serve as the benchmark, at least as far as the BMC part is concerned. AutoCAD should be able to provide that, and a blueprint printer should be able to produce it.
Hopefully, everything will be in place to print it on Wednesday.
hmm, like this?.....note stubbie of CUB Abbottsford Invalid stout...
Noted - and now I'm thirsty . . .