Hi Davey
I purchased a 7mm DJB Q Class kit from Ace Products about a year and a half ago it looked a bit involved to me as it had quite a lot of parts as I have only built a 0-4-0t loco so far so a builder called Nick Dunhill has the kit to build for me in about two months from now I have had him build locos for me before my two LSWR/SR O2s are on his Flikr pages they were painted by Warren Haywood I will get feed back from him after he has had a look/started the kit and let you know if this helps.
Regards,
Paul.