Have you tried Club Triumph or the TR Register? One supplier I would recommend besides the usual suspects is S&S Preparations who are TR7 specialists. They're quite handy for me as there's some overlap with the 1850/Sprint.
West Yorkshire Area Organiser & forum moderator
Meetings take place on the 1st Wednesday of every month at The Hollies Sports & Social Club, 12 Hough Lane, Bramley, Leeds, LS13 3NE
Dolomite 1850 auto (NYE 751L - The rolling restoration)
Citroën C4 Grand Picasso 2.0 HDi Exclusive (MA08 WCL - the modern)
Former stable of SAY 414M (1974 Toledo), GRH 244D (1966 1300fwd), CDB 324L (1973 1500fwd), GGN 573J (1971 1500fwd), DCP 625S (1977 Dolomite 1300) & LCG 367N (1975 Dolomite Sprint) plus 5 Acclaims and that's just the Triumphs!
Check my blog at http://triumphtoledo.blogspot.com
"There is only one way to avoid criticsm: do nothing, say nothing and be nothing."