It's my theory that those early 3SW's were Khaki painted civilian model 3SE's (E=Economy)

Ron

email (option): ronpier@talk21.com

So it would be appropriate for a bike from either of these contracts to have an 8” headlight
The smaller headlights associated with the 3SE models impressed in the early stages of the war
Job

For the two contracts that you've mentioned, I'd say definitely 8". Looking at photos again though, it seems that the early part of C5108 might well have had the smaller lamps too. This was also a late 1939 contract.

It seems that by 1940 they had standardised on the larger headlamp.