Best bet is to get in contact with Rob Harrison - Sorry, Rob Hamilton.
He will be more than happy to bend your ear about EVERYTHING that opens & shuts with a Harrison - you'd think he worked for them.
Rob is a very knowledgable guy who investigates everything he does to the 'n'th degree and he is very happy to help anyone who asks & is willing to listen.
I'm not sure if he's on the forum or you can contact him through Vic Cobra Club.
If you PM me your ph# I can forward it to Rob & ask him to call you.
Cheers
Batman