Agreed....I was gonna write something, but read yr comments...I've had Dayton with grey shells at #70000 with Bow ties ...Also had Dayton with grey shells at 85000 with the larger T handles..So I think the answer laids in between here...!
For a few years now, I've been trying to document when all these hardware and shell changes occurred for Rogers, but as all Rogers guys know, those changes don't really correspond perfectly to serial numbers (which were pulled and applied almost randomly). I've based my estimates for changes on observations of actual factory-original drums displayed on this site and others.
This issue of bass T-rods is especially confusing, as the 1966/67 transition period saw a lot of changes (Faucet to flat T-rods, Dog-Bone tom mount to the newer Swivo mount, "blips" or shoulders appear on the square heads of tension rods, twisted guards on the Dynasonic become "fold-over", Dynasonic shells go from 7-line to 5-line, etc, etc, etc.) So I've seen Holiday basses in the 68xxx Dayton range with factory-original flat T-rods, yet (as Rims points out) "later" 70xxx serial numbers with faucets! Obviously, the 68xxx bass with flat T-rods is actually "newer" than the 70xxx with faucets.
Compounding the confusion caused by workers applying random labels at the factory, individual 1966 shells could sit in the warehouse and not be assembled until 1967. Precise, year-of-manufacture dating for Rogers is an estimate at best. Here are some actual Holiday label observations of transitions:
Highest B&B lug Holiday observed - #35327 Cleveland
Lowest Beavertail Holiday observed- #36131 Cleveland
(so the lug change was somewhere between 35327 and 36131? Nope! Cleveland #37819 had B&B's!)
Highest Cleveland label observed- #61149
Lowest Dayton label observed - #63258
Highest Holiday with gray interior - #83883
Lowest Holiday with speckled interior- #88308
Still working on narrowing down the changes in other hardware (tone control pads, lug screws and washers, machined vs. cast collet noses, etc). I don't do any of this tracking for dating purposes; I do it just for restoration purposes so I know what hardware I should put on bare, orphan shells.
Sorry for such an extended post, but please, if anyone has similar pinpointing of Rogers changes, let me know.
Mike