Many thanks for your reply, I am in touch with Criss Storrar who lives near by and we are meeting today Friday 4th Jan so should be able to get some of the other questions answered. Regards Firebird Roy [quote="g7psz":k3sqnjcd]The temp gauge is obviously 2.5 inch diameter -the same as on my Speed 20. These are quite scarce; the last one on Ebay I think went for about £180. The usual diameter of small gauges, including capillary temperature gauges (the capillary is filled with ether by the way) is 2 inch. I made an aluminium conversion disc to allow the use of a 2 inch gauge in the dashboard hole. It does not look quite right but at leat I can tell when the engine is getting hot! In the meanwhile I am keeping an eye out for a non-working one because the ether has leaked out or the capillary line has been cut off. I have fixed these gauges on my post war cars by making a male and female brass connector which I soldered into the capliiary line which I had cut, filling the bulb with ether and then screwing it up. It needs refilling every 10 years but sure beats wrestling with sealing the filled bulb with a sodering iron whlie the ether flames away (it is hightly flamable). I cannot remember what the thread in the head is. Take out the plug and get a suitable adapter from a plumbers merchant to get the capillary bulb to fit. Steve Laurence, DYE 166.[/quote:k3sqnjcd] Posted by Firebirdroy 04/01/2013 10:04:00