Found info dating the 82001 engine to 1961

I was looking at an old Power Bee manual trying to find a part number when I noticed that it dated the 82001 engine as being originally built in 1961. Until now the earliest 82001 build documentation I could find was from March of 1962. Since the engine serial number is 1017 I suspect this is the 17th 82001 engine built and it was probably built in 1961. Possibly the MK0 is a 1961 bike???