Yup, Wiscombe Park is organised by Woolbridge Motor Club see..
http://www.woolbridge.co.uk/ a lovely group of people, well worth supporting.
There is Gurston Down Near Salisbury,
www.gurstondown.org
The rest of the scene down that way mostly revolves around sprints and Rally. I suspect Torbay MC would be good people to talk to ...
http://www.torbay-mc.co.uk
Thruxton isn't too far either ..
www.barc.net