Hew is a mismarked siamese (blazed on nose).... note the tan color as a baby
There are like 9 different varieties of rex that go from looking much like a standard, to short coat, patched, naked, curly, whispy, etc
Back to the OP: The trouble with breeding a pet store or feeder bin found "hairless" variety is not knowing the genetics & not knowing if you would run into lactation issues.
I'm not real sure why you are seeking to bred the hairless as feeders outside of just having a naked rat rather than a haired one, but I would laike to add to the already good chance of finding lactation issues, the hairless are notorious for having small litters.