Speaking as the host of
www.touringcarracing.net, feel free to check and use data from my site (but please give credits) - if you come across any errors please let me know. Your 1979 Donington results give at least qualifying times which I don't have. My sources are mainly Motoring News, so together with Autosport that should give a better picture of the BSCC/BTCC.
Love the layout, by the way!