RV history check resources

For what it is worth, if you find the previous owner, then you might look for a forum for brand specific RV's and see if the owner was a member and had posted about his RV.
One of the forums I belong to is for a specific types of RV's and if you were looking to buy one it could educate you on common issues and solutions. If the previous owner was a member, you might be able to read where he had some serious problems that were either corrected, or might be a remaining issue for a new buyer.
Basically the internet is your friend. Use all of it to gather information about any major purchase.

CarFax does not list previous owner information, only the number of title transfers.

Never heard of RV Check; Carfax is only worth just about the value of the paper it's printed on. Many things will not show up, including owner performed repairs, and often even major things. I bought an H3 Hummer; Carfax was extremely clean; one owner, no accidents, regular maintenance performed by Chevy dealer...after owning awhile, I have found unmistakable evidence of a major right front damage/body work. Nothing about it on Carfax. I assume that RV Check would be similar.

Doubtful any of them would list previous owners, with privacy laws and such.

I ran a CarFax report on my coach being a used repo. The only info was associated with the registration and title changes.

In many states, engine powered vehicle registrations is public information, and can be gotten by submitting the VIN to the state licensing branch, or local PD.