Thanks Peter.
It wasn't that hard to remove the fan, just well supported the fan on a solid base and 2 firm hits on the shaft end with a hammer and punch to loosen it, then it tapped out easily.
There is no flat on the shaft. It is round with a knurl/spline cut on the end.
After having a closer look at the pcs I' m going to go ahead and get a motor, assemble my fan and test it out. If fan shows signs of being loose I'll apply some glue.
Sad they don't sell new motors with fan. Can't find anyone who even sells fan alone.
New regulater just incase the present K.A.E. year old is malfunctioning.
Motor & regulator will be $292. compared to $861. for assembly.