vintage girling fluid reservoir cap automotive replacement part for british automobiles

vintage replacement part for British made automobiles... a cover or cap for the hydraulic or break fluid reservoir tank. We're not sure exactly what makes and models this fits, but I've been told this is for britsh vehicles like Jaguars, Land Rovers, Austin Healeys etc.

It's marked "Use Castrol Girling Fluid Only" and measures approximately 2 1/16 inches across the outside and 1 3/4 inches across the inside (or approximately 50mm and 44mm across, respectively).

This is not a new part. The rubber looks gasket looks good and the metal has wear and light rust.

this item no longer available
Item No. nt102510