There's an ad for the Animal Fun issue in "Nuts!" #1, otherwise I might wonder if was even the same Premier Magazines that published the 3-D issue. The issue also has "Billy and Buggy Bear", who appeared in Timely books in 1943-1946... and Charlton books in 1947. This is just an odd book at best, it seems; it seems to be all (or almost all) Marvel/ Timely inventory. But the Charlton appearance suggests it's not impossible Marvel let the material go; Charlton's rep is more for grabbing stuff others don't want cheap rather than actual theft. This may be a rare case where I scan the book to share it elsewhere; I suspect it's legitimately in the PD even if we have valid reasons to not post it here.