The breeder may well have put an 'endorsement' on the registration, to say that no progeny could be registered, if so this would need to be lifted by a letter to the Kennel Club from the breeder, which they would probably only do if they thought it was good enough to breed from and had been tested free from any hereditary defects. Min Pins can suffer from patella luxation (slipping kneecaps) and also eye conditions.
If you know about breeding horses, you will probably realise that you wouldn't take your mare to any old horse up the road, you would find a stallion that would produce something that you wanted. Its the same with dogs, owners of bitches plan their matings carefully with a view
to improving on what they have got. Let the breeder know you would be willing to allow your dog to be used and they may have a bitch or know someone who has that your dog would suit.