I think there is still a chance of testicular cancer if not neutered.

I think that a lot of times people ASSUME something..
 

and do not realize that new people come here for advice, not condemnation. I think that earlier responses assume that you are an "experienced" breeder since you stated that you were interested in breeding your young male....and usually the more experienced you are, the more apt you are to know .....what the standard is, etc....thus the comments.....I do not think the young ladies meant anything other than "opinions."

And I too will give you mine....LOL.....and believe me I have learned a lot from many of the people here too......the big thing that you are dealing with is, size...and the issue of staying within the breed standard.....and your male is not.....and you were still willing to breed him. As far as the seller goes, I do not think she would have known about sterility unless she had a reason to know....ie....trying to breed him before you bought him......but, I do think she knew your intentions and she should give you some compensation....more so for the sterility than the size issue......as size is a lot of times left out of a contract, because it is so hard to predict......but, on the other hand, who would be the best to predict size, than the original seller......so ......sounds a bit fishy to me....

Good luck to you, I think I agree with one of the comments...neuter him and move on to a different breeder.:)