Going from memory here, but according to a materials science professor at the University of NH (70's era), the plasticizer is breaking down in these wraps causing the molecules to separate. Short story - plastic doesn't last forever. Example - automobile instrument panels in the 60's era, for which this guy received a large grant to solve/reduce the cracking problem for the future.
Only time will tell, but the new wraps may last longer than what was used during the era in which that red onyx drum was made because of improvements in plasticizers.
Regarding new wrap; the newer onyx wraps have a bit more horizontal pattern that is closer to what you saw on drums as the end of the Holiday era was approaching (Fullerton, CA). The earlier drums tend to have wrap that has a wider more vertical pattern with more red and less black. There is a Fullerton set for sale on eBay right now that has original wrap that is very close to the new wrap. A shot of a red onyx kit with new wrap also attached. It's not as clear as I might have hoped. Light wasn't very good that day.