oil pipe fitting size variation button to gauge

[JonE]

Thanks for all the advices. I'm going to keep simple and save weight by abolishing all the present joints and just using my newly acquired, self-renovated manky Harcourt gauge for a permanent fixture. (I really want to use the other snazzy aircraft gauge which also has 1.8BSP fitting, but its bigger and heavier and I don't want the car to get too much attention from bean counters... or to gain pounds)