Mk1 return relief oil deflector (inside crankcase)

[allan.walker]

Not your original query, but related to oil level in the crankcase:

Have you checked that the oil pickup pipe in the sump aligns with the hole in the top of the oil filter mesh? I have two of these where the hole and soldered ring is out of alignment. As a result, the pickup pipe rests on the top of the mesh and this can only restrict the return of oil.
The pickup pipe is not out of its correct position and it cannot be 'tweaked' to align with the incorrectly made filters.