This is the small red fibre gasket that was fitted on to the lipped steel union on the outside of the gear oil pump fitted to all Side Valve and Overhead Norton models - and connected the oil feed to the outer timing cover.
Fitting Notes: This gear type oil pump was fitted to all Norton OHV and Side Valve models through the mid 1920's to 1950's. As can be seen from the photograph of an original oil pump (this one coming from a 1940's OHV engine), there was a small shouldered steel connector that pressed into the outermost face of the oil pump, which mated with a corresponding recess in the outer timing cover.
A red fibre waseher was used to give a seal between the two.
Fitting Notes: As this design was fitted for many years, I have seen minor variations in the machining tolerances of the steel shouldered connector that the red fibre washer presses over. Therefore it is always a good idea to ensure that the fibre washer fitted will actually touch the timing cover mating face (it should just touch as the screws are tightened), to ensure best feed of oil. There are various ways to do this - one of the ways I use to use was to mark the outermost face of the washer with 'Engineers Blue' marker paste, then ensure that marker touched the timing cover recess as screws were tightened. Obviously, whatever method is used - it is very important to ensure nothing enters the oil passageway.
These red fibre washers are the correct outer and inner diameter to fit over the steel shouldered connector correctly. They are 30 thou (0.77mm) thick and you may find you are able to fit two washers in place to get a good seal. Price is per pair