Actually since I didn't see anyone crawling out of the woodwork to defend the "variable size hoops" theory I decided to look closer at the drum and certify that the hoops are infact the same. To me it looks like the lugs are drilled slightly lower than center on the shell, which exaggerates the appearance of the angle on the top rods, but both go towards the inserts at the same angle top and bottom. It just appears more drastic due to the way the shell was drilled--which is not perfect and the fact that the bottom head is tighter--therefore showing less tension rod.
I've seen this before on other Jazzfest drums where the depth varied a bit causing lugs to be slightly off. No one ever pointed it out as a problem before. Not to say it's not a personal preference when purchasing a drum for a collection, but either way this is a way more likely explanation for the angle we see--at least in my view (with the drum in my hands).
Anyway...whatever. Ludwig drums from this era aren't even round...so it's not like it matters for playing. They sound awesome and this drum is no exception.
Adam