I thought I'd try work? And whilst there I undertook some Team Thumper business by having a long and interesting chap with the founder, and brains behind, Tigcraft, Dave Pearce. Gave me a lot of very good and time saving info., such as this interesting fact:
An SRX/XT/XTZ motor will produce more horsepower having a 'conventional' rather than 'oil-in-frame' oil tank. Apparently this is due to crankcase pressure!
Then I went home and put up some curtains........

Boyd