Used to ride a Cushman just like that in the late 50's.Mine was a little rattier looking but I believe it was a late 40's model.About 40 mph with a tailwind.Had a special starting procecdure with that ratchet start lever.Brought a lot of memories back after seeing your picture.

 

I rode philm's scooter and it is really suprising how fast it is. sure did suprise me thats for sure. 0-70 just like that! No big deal!