Pied Pugs

Hi, we are on our second litter of pugs. Mum is black with a very small flash of white on her chest and Dad is fawn. We have 3 beautiful blacks, again with Mum's tiny flash of white. But, we also have 2 pied puppies. OMG they are stunning, probably equal amounts of white to black. Obviously the KC wouldn't register these ( parents are not registered but assured full pug ) Does anyone know where I can gain information on these or see pictures of pied pugs ? I have learnt that either Mum or Dad carry the S Locus gene. We kept their son from their first litter, would have definitely carry the gene ? What about pricing these oh so special babies ? Thank you in advance for any information supplied.