When you look about how to do it John, any "official" advice will probably only tell you how to put it together for the "standard" wheelchair user, and there's no such thing. Have a word with your local shopmobility people, and they should be able to give you a good idea, as they'll know lots of wheelchair users.
As cold as those toilet seats in the toilet block get though, the idea of pre-warmed seats is just wrong
