I was looking for several slipcovers and, aside from Disney, I couldn't find any information to contact the companies. I was looking for the cover insert and slipcover for Superhero Movie Extended Edition, but couldn't find the info to contact Weinstein/Dimension. But even if I did, they probably wouldn't have any covers and slips still available.

Ok?

The few times I tried contacting studios about missing booklets, my requests fell on very deaf ears. There are sites like http://cdcovers.cc that offer low-ish-res scans of inserts, and sometimes you'll find a poster on this site unloading a handful of slipcovers. Otherwise, I suspect the best way to accomplish what you want is to buy another copy of Superhero Movie. Maybe you could unload your current copy at an FYE for $1?

Fox, just once, sent me a cover. But refused when I asked them for another. But Disney, on the other hand, has sent me every cover that I've asked for....well, all except for the older ones that they seem to have run out of. Oh, well. It's not that critical. If it was one of my favourite movies, it might be more of an issue. But it's not like I'll watch it all that often.

I would tell you to contact Genius Products Inc. They had the distributing rights for home release. You could just buy the blu-ray too? But yeah, I contacted FOX for a slipcover and they said NO and told me to return the item for one that had it.