I enlarged the photo and these are the serial numbers I see:
floor tom - 112xxx
bass - 89xxx
tom - 81xxx
snare 17xxx
The numbers are not that far apart, and the ride tom has a very late number for a flat grey Dayton drum - probably made shortly before the switch to speckled paint.
The very light paint inside the bass makes sense: it has a low serial number for a speckled Dayton drum - meaning it's an early one, and they did not settle on the well-known shade of speckled grey for a little while.
Those shop stickers are all original and well worn. They tie this kit together in one of the best ways possible. I have little doubt this kit was delivered as a set. The drums were obviously built during the early CBS transition, and they were built in the midst of significant production changes being made. The bass being a lefty and the tom being a lefty tie them together as well.
Franks was a big shop and moved a lot of drums. It's possible that they assembled this kit from single drums they had in stock prior to delivery. Dealers did not always keep kits together and often had orphans on the shelf so they could gather what the customer wanted and get them out the door. Again, I have little doubt the kit left the shop together.
The stickers also are proof that none of these were rewrapped.
Too bad about the cracks on the bass seam, but they're not serious.
Overall, a special kit, in my opinion. And worth close to the asking price.
By the way, those serial tags had to be dampened like an old stamp before being affixed to the drum. I've seen others that also looked to have been saturated and then dried.