So much awesome information in this thread that helped me with my collection of this set. I don't have any of the uncut sheets/information to contribute, but did pickup a few oddball and what seems to be printer waste that I've never come across (no reason to believe it's not legit, but maybe someone can shed some light) so thought I'd share.
Printed on 1975 Topps Football backs
1974 Marvel, 1975 Topps
Not stickers and not die cut
Color registration is way off so probably test prints on new plates/press
Looks to be handcut and a terrible job at that
Terrible condition so maybe it was cut from a tossed out test sheet
All **, at least the ones that are visible
Purchased from Connecticut (don't know if they did any printing there for this set)