Dave - Seems there are exceptions to any rule made about cosmetic features such as serial numbers, coins, tip overlays, etc.
The form the bow was built on really determines the year, not an incorrect number an employee wrote on a riser for one of a hundred or more reasons, e.g., first or last day on the job, filling in for someone who was sick, mad at the boss, hung over, in a hurry, lost a contact, goofing off, etc.
The 63 in the photo has Brazilian Rosewood Caps and Bubinga Riser.