It is possible, but very unlikely his testicle will drop at his age or older. You should have received a price break on him because the cost of neutering is going to be higher than normal. I would use a vet familiar with stomach tacks and have that done as well since they will be in his abdomen anyway. The tack is to prevent stomach torsion in case he ever bloats. I think the techical name is gastroplexy or something similar.