Hello ..There is a Triumph , Simms type fuel gauge in the (appx) top centre of the rear face of the main petrol tank , just to the right of the MG cut out / trough.
Without digging out and checking the original Drawings , I'd say , from memory , that the glass face is about 2" dia. with the surrounding Aluminium bezel being a Hexagon, (6 sides) being about 2,5" A/F and which is screwed to the bronze flange , riveted & sweated to the rear tank face .
This gauge is operated by a cork float on the end of a wire arm .
The gauge can be read by the pilot ,... the line of sight being over the MG ammo container , and to the right of the (Vickers) MG.....Some daylight is provided by "Windows" in the cockpit combing .
Regards John M
PS..... A similar , but slightly larger earlier model gauge is fitted in the rear face of the BE2b service tank ..... If you care to look up " My BE2b Reproduction" , an old thread , there is a photo of it there .........( That will save me from going through a lot of SE stuff .

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