Thanks Carol.
Your experience certainly adds weight to the argument to leave his castration for as long as possible. Though I could not cope with the inappropriate weeing! Any sign of that and he will be hot footing it to the vets!
I shall be seeing his breeder in a couple of weeks so I shall discuss with her how long she thinks we should wait. I only intend to show them as neuters once they get too old for the kitten classes.
So her hair should be re-grown in 4 weeks being a shorthair? I shall ask the vets if they can do as small an incision as is practically possible.