Michael,
Not to be a booger or anything (I'm just asking a question here) but are you trully seeking our input or are you merely looking for validation of your already arrived at decision? Seems to me you've already chosen a path here.
Just to echo my friend and neighbor (sort of), kb3csw, these old Stovebolts forged a legacy of dependability and ruggedness doing a hard day's work without "blowing up." Personally, I still use my '49 around the farm and make regular runs out on the big road with the original (but rebuilt) splasher 235 and it has yet to "blow up."
Does it keep up with regular traffic? No, of course not. But the originality of the truck (including it's slowness and degree of difficulty to operate as compared to modern vehicles) is the charm and attraction that draws *me* to these vehicles and I adjust my way of living appropriately -- For example, I plan enough time to get places at 45 MPH instead of 70. I allow more distance between me and the vehicle in front of me because I know my brakes aren't anti-lock and I don't drive it like I do my daily driver.
If that's what you like about working with an old truck, fine. Leave it original. If you don't, then by all means modify it as you see fit. Just be careful with using sweeping generalizations that may not be accurate to validate your decision.
As far as keeping the original drivetrain after you move the sheetmetal over to a modern drive train -- don't bother. The mods you'll probably have to make to mount the cab and sheet metal to a modern frame will most likely alter them beyond the point where it's feasible to return them to the original frame down the road. You'd probably be better off making the parts available to somebody who's trying to preserve their original truck. That, and you might be able to recoup a few dollars to put towards your project.
And by the way, as a working truck, my '49 would probably get laughed at by judges anywhere, let alone at Hershey or Carlisle. But I have been known to trailer it on occasion.
Regards,
John