FISCAR's calendar here:-
http://fiscar.org/
Additionally, I'm running (and I did consult the HSCC first!) the Archie Scott Brown race at Snetterton with VSCC on September 17th. Yes, I know it clashes with Spa but you have to work with what you have, and hopefully those who cannot get to Spa for time/distance/work/ whatever reasons will be able to give one day over to Snetterton to remember this legend of a racer.