As Danny stated, there is no way to tell by looks. You need to make an attempt to contact the breeder and ask. Price may be able to help you determine, as generally, VPI line animals are the most expensive, with Joliff and TSK lines being less desirable and less expensive (there is a long history here and I am not trying to be demeaning, but stating the facts).

p.s. I do not know anything about GBU enterprises.