I am cleaning the oil strainer on a 2L Type IV motor in my 1981 Westie for
the first time (under my ownership).  I bought a gasket set that includes
the two large paper gaskets and the aluminum crush washer.  However, when I
took the strainer off, in addition to the three gaskets I have in the kit a
fourth rubber washer came out?  I am not sure where it came from but it
came out with the strainer itself.  Also, it's split and I assume it should
be replaced. Looking at the parts catalog I have I see no mention of it.  Any
ideas guys and girls where this goes?