my thoughts as well, looks too scruffy to be the curly full coat rex
The "nakeds" (far too many hairless varieties to know which type), they shed out starting with top of head, down the back & typically the last to go is feet, bum & face.
High maintenance indeed & in many ways-- from easily injured to being temperature sensitive. I worked with a few litters a few years ago & they just don't seem to be a hearty animal. Loved them warm bodies but overall health was just no good. (i.e. lactation, kidney, short lived) I know people who have continued beyond where I jumped off & they have high frequency of CHF, kidney failure & a plethora of other issues that have always been enough to stop any line, yet they proceed <shakes head> All of this is why I don't breed to express anything in the hairless varieties. Rex yes, but not double rex or anything of the "naked" varieties. As a side note I have read about another variety that some people in my area have been working with-- the patchwork lines. Many of these have all been expressing major eye issues.
It's all a real shame, I rather like the naked rats but I morally & ethically do not care to pursue genetics that produce a large percentage of poor offspring. Maybe someone out there will get it right & not fret a culling process.
Enjoy your scruffybutts but please do a fair amount of research before you venture into reproducing them.