First off, thank you so much for your offer, and howdy to a fellow '66er! :hello2:
Tried this at my local Ace and ended up taking home a bunch of different springs, all of which were close but none of which worked "just right" as Goldilocks would say. I think the problem has to do with the original part no longer expanding or compressing to its correct lengths. I measured the gaps and tried to compensate, but "chose poorly" as the guy from Indiana Jones would say.
If I'm lucky enough to find an intact replacement, I'll post the exact measurements here for anyone else that might be looking for one.