I like your camper idea, for years I've been day dreaming and collecting pictures of original aluminum/metal camper tops. I intend to make one real simple with just fold down cots/bunks on each side, more a truck cap than an actual camper. That'll be a few or many years down the road yet.
I searched too on the bearings, It seems that the imported/aftermarket tapered bearings that were available a few years ago are no longer available.
The original ball bearings are available and while not cheap aren't ridiculously expensive either. They also work quite well, really nothing "wrong" with ball type wheel bearings.
Here are some of the more useful threads on the subject of swapping/adapting more common tapered bearings.
https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/629388/Grigg.html#Post629388https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/821239.html#Post821239https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=956511I don't know of anyone that has followed up on the bearing swap idea and made it happen.
One of the unanswered questions is the grease seal behind the inner bearing which originally runs on the extended inner bearing race, unlikely a tapered bearing also allows this.
This Timken catalog might be useful.
http://www.timken.com/en-us/products/Documents/Timken-Tapered-Roller-Bearing-Catalog.pdfThere might be a decent solution if you're willing to do the research and decide what off the shelf bearings and then what machine work, bushings, or spacers might be necessary.
Let us know what you come up with!
Grigg
