At last, through a heads up from Rick the Serviglide that was once owned by Gary Wollard and then by Wayne Mahaffey has been found. Some of us may recognize it when it was green as Wayne brought it to Portland several years back. It was then sold to a new home in Washington State. After that the bike was disassembled, repainted and chromed. I contacted this person to get the engine number as the curiosity was killing me. He had taken several photos of the restoration. He has done many motorcycle restorations.
The engine number is 39D 323. The Simplex manual clearly defines the 1939 from the 1940 in that the 1939 uses wingnuts near the rear axle to fasten the side covers while the 1940 uses springs. If you zoom on the green bike photo you can see the wingnuts.
It has been stated that Simplex made four 1939s and around one hundred of the 1940s. In addition, the 1939s were green while the 1940s came in bright silver for its safety at night.
