Mmm, funny,
I did not notice before that this A9764 contract number was also used to buy BSA motorcycles!!
Number used for 500 +100 Norton machines delivered in 1938.
By that time the magdyno end cover was flat, not lobed, so it was an older picture used in the manual and shown in the C3655 lubrication and maintenance chart!
The 1937 Nortons had the lobed cover, 1938 not.
C3139 and C3655 were also mixed contracts. That I did notice before.