Make Diesel a solid light gold with one blue eye, and he would look like the purebred Golden that was in our Rally classes. Yeah, seriously. She got him through rescue but he originally came from a pet store. BUT- honestly, I'll guess GSD mix (his head looks very GSD to me). I want to say mixed with Toller, but I don't know how popular Tollers are by you. If they aren't popular, he could have some Golden in him, maybe Collie too.