Looking across the mowers I have from the 61 - 63 period, there is and identifiable model pattern, it seems to me the 60's brought in a crude attempt to make the serial numbers more than just a numeric sequential string, as seen in the 50's.
I've found enough to be able to identify the serial of an early 60's corvette, and further, unlike the chaotic serials of the "get them out the door" 50's, they had already revised the serial system in 62, as you can see by the year code apparent in your serial, that is not seen in a 50's serial.
Anyway, seems worth a shot to me, as I really don't see how you can be sure the heritage of a confirmed bitsa.