WLC Serial Number Markings???

[Johan WILLAERT]

I'm working out markings for a Canadian Army Harley-Davidson WLC motorcycle with Engine Number 43WLC5668.
Unit markings will be 3MedRegt/RCA attached to 1 Can Army 1944-1945 (just like the attached image). The stencils for these markings have been cut and the vehicle should be marked appropriately before it's next ride.
That still leaves me with the bike's Serial Number. The new book by Jean Bouchery on the WW2 Canadian Army has been a great help but the only picture of a WLC in it has the front part of the number covered!!!!! What would be an appropriate number for the WLC in question. What were the numbers that were used from 1943 onwards.....(which were different style I think of the ones used on bikes prior to 1943...).....
In that same book, about 90% of vehicles shown on wartime images have the serial numbers start with 42 directly after the lettercodes (for instance CM42xxxxx).
Is there a reason for this or just coincidence???
Thanks for any info,
Rgds, Johan