There is an actual Selman company making what they're claiming to be good student instruments, they're all over e-bay but I'd be cautious about buying one.
I purchased a 4-valve Selman tuba from Greattunes on Ebay and it was defective, didn't play appropriate notes for fingering. No one is able to fix and of course the Ebayer would not take back or make right. Beware, trading on Selmer name I believe.