Its pretty short, I bought mine from Robsport under part no. GFB295K but I think the "K" suffix may just be their indicator its used with a Kenlowe so the number may not be very helpful.
Rimmers list GCB10788 (TR7) or GCB10737 (Dolomite 1850/Sprint) and rummaging round on the Dolomite forum it turns out the last three digits are the length in mm. So you need one approx 737-788mm long.
I'll try to measure mine tomorrow if possible and see what it is.
Russ
1980 TR7 Sprint DHC
Dursley
UK
http://tr7russ.blogspot.co.uk/
