mk1-forum.net

From the link I posted above:

GTR102 - Green Insert. Used up until 09/64 when the voltage stabilisers were introduced. Smiths marked TT-3800/00A, Intermotor 5270
GTR104 - Red Insert. Used from 09/64 until 1969 with voltage stabiliser. Smiths marked TT-3802/00, Intermotor 5271

Cheers Timmy, just gotta find one now!

Hi all, finally successfully got temp gauge to function correctly! Yeah! A big thanks to all who took the time to answer my often inane questions about the patently obvious! Much appreciated

What was it in the end

Fitted the correct green transducer with original gauge, ditched the non working 2nd hand gauge and bobbies yer aunties bird in the bush! Thanks again all.