Hmmm..I just double-checked my '69 shells and they do not have the wrap tucked into the scarf....AND, the shells are stamped from JANUARY, 1969. Weird, huh?
A slight oddity on my '69, 12" tom tom is that the small lugs are mounted closer to the ends of the shells than on my '67 12" tom tom. I've seen other tom toms where the lugs are mounted closer to the middle of the shell, too. I would have thought they would have been using some kind of jig for such measurements...but, in some cases, it seems just....random!
I can't explain why your APRIL, 1969 shells have the wrap into the scarf. That is a weird one...(to me, anyway).
Hypothetical Situation #1:Maybe someone called in sick and a former shell builder filled in for them and just forgot to do it the "new" way and made a few clear, maple interior shells the way they had always done...and just stamped it and put it out there. *shrugs shoulders*