There were several lab x greyhounds in my village when i was younger. Most were used as gundogs and ferreters and one was a decent lamp dog, and another put up a good show at coursing hares but was obviously no match dog. All of them retrieved and i am surprised the cross isn't more popular.
My brother had a Russell/ poodle x whippet and she was the clevererest little ferreting dog i have seen so far. She could jump a six foot fence and swim well and looked like a small woolly whippet. She may have been a one off though.
My Mrs. used to walk the russell to school with the kids and a farmer had a lakey type that was the local dog bully, always off a lead. She used to pick our dog up when he ran out but one time she didn't see him and our dog gave him a sound thrashing. Trouble is he walks around now thinking he's Lenny Mclean.
There are a lot of people who just buy ferrets at the start of the season and sell them when it's finished, they have no affinity with them they are just disposable. They moan and whine when people charge more than a tenner for good working stock and would tell you " just get another ". They have no concept of the man / animal relationship and i expect never will. I genuinely feel for you buddy.