I have in my hot little hands two F4's.
One is serial number 67236 with a FON = 11495...cremona brown...aluminum bridge top and no truss rod
Second is serial number 66587 with a FON = 11495 red finish...aluminum bridge top and no truss rod.
Both are in really really good condition.
So why the wide variance in serial numbers with the same FON......Perhaps instruments sat around for a while? ...large batches?? lots of elves making lots of instruments at the same time? Beyond my little pea brain....
I started another thread on this rather than jump on one of the other threads of serial numbers on Loars or the couple of F4 ones going on now.