Hi again. Not sure where you got your info about Black Sabbath playing at the 'Art College' - The only 'Art College' I can recall, at the time, was in Canterbury ( we played there sometime in '74), not Folkestone...?
Also, according to the Black Sabbath website: SABBATH ONLINE, which lists Sabbath 'archive' gigs: http://www.black-sabbath.com/tourdates/1970.html - from 1968 - 1971, only Tofts in Folkestone is listed in April 1971. The only other gig nearest is in Lewes, Sussex.... But perhaps others know more? - Steve