Hi Traveler,
Might I suggest moving the exhaust pipe forward where it is attached to the frame. The reason I mention this is to round the pipe as it leaves the exhaust manifold to remove the stress from the junction where the pipe enters the manifold. I will enclude a photo of my 1950 Schwinn Panther with the same exhaust setup. The photo will also show you have your motor mounted correctly.
Your Whizzer is looking good!
Have fun,