It's certainly the case, even with modern blanks, to set the rings on the outside of any curve - but not many modern coarse fishing blanks have alignment marks, of course, so you don't have the (very minor) dilemma I have with alignment marks. If I have to turn the tip 180 degrees, I'll do the same with the butt section too, but I'm more inclined just to leave the dots on the underside and accept that any droop is minor, won't affect its ability to cast or catch fish, and is part of it being an old rod.
Further update - I've cleaned the blank along its length, and used fine wire wool to remove what little varnish residue there was. The pale patches where the whippings were are still there - I'll photograph later. I have some red root oil that I think will sort them out, which I'm going to have to do unless I want either a patchy blank or to compromise on ring positioning to hide them. That always assumes that the cane will take the oil - it might not.
The one blessing is that the worst of the mis-positioning is on the butt section, and those rings - which never even got as far as being varnished - have been on for such a short space of time that no harm has been done.