From R Blake Stevens North American FALs:
(Not counting the FN CDN EX-1 and 2 trials rifles and toolroom prototypes);
0L0000 - 0L5999 Rifle 7.62mm FNC1
0L6001 - 2L9659 FNC1 with modified magazine catch, bore reduced from 0.300 to 0.298, bore and chamber chrome plated.
2L9700 - 6L5374 FNC1, rifling groove diameter reduced from .310 to .307
6L5375 Production halted due to to pirced primer scare; 7,399 rifles remaining in the contract
6L5376 - 7L2775 contract completed with C1 rifles
NOTE: Many early C1s were handstamped "A1" when routinely overhauled and converted to C1A1 specifications, under maintenance contracts placed with Canadian Arsenals Ltd.
8L0001 on late productiom "C1A2" rifles. Highest number seen, 8L5018
[basically every 10,000 rifles, you add a number before the L, 0L5999 is the 5999th rifle produced, 8L0001 is the 80,001st rifle produced etc]
one C2 (0L0001) was produced with the same serial number as a C1, after that , C2 serial numbers were xLA###, highest C2 number seen was 3LA897
Hope this is what you are looking for.