Looks like a simplex from a distance. Frame looks professional. Some welding, mostly brazing on brackets, ect.
Tank, center fill, 17 inches long. Longer then any simplex tank we measured.
Frame in rear loops around instead of two tubes terminating at the wheel.
Front forks are 1/2 inch, one piece all the way thru springs, larger then two piece simplex.
Crash bars extend under bike until they meet, and smaller diameter.
Drive train goes from belt to jack shaft, to chain final drive.
The engine moves on rails by pedal to tighten belt. A one way gear holds motor/belt tight until cable to handlebar lifts gear, releasing engine to slide back and loosen drive belt.
Brakes are on outside of drum and contract using pedal on right side. They look totally inadequate.
Rear sprocket is monarch super with bracing in three places to rim.
Handlebar controls are prewar schwinn.
Fenders are prewar schwinn.
Seat leather is simplex.
Footboards are different, bigger and wider then my other simplexes or bikes.
No serial numbers to be found.
I added the Deco-Grand engine.
Bought at portland 2020 and payed too much,,,but i liked it so I don’t care.
Edited for spelling.