I am commenting and have only read the original post, have not read any replies so forgive me if i am repeating other posts or whatever
i had an italian greyhound that only had one tes come down. he was neutered and fine after that. but he was about 9 months old when he was neutered.
i would talk to the vet and see what they suggest, chances are they will tell you to neuter him. and if you were hoping to breed him, yes, I would talk to the breeder. i really wouldn't bother with talking to the breeder about it as long as he is neutered and healthy. you could mention it but they might just say "well, you can bring him back if you want" and i doubt you want to do that
if the surgery is expensive, you could ask them to help with costs but i wouldn't hold my breath. but she should know about it for her future breedings....
good luck to ya hon!! i really think your baby will be fine, you just need to have him neutered to avoid any health problems down the road.