[Amps] L-4B blade/blower replacement

[Garry]

Has anyone had to replace the blades or blower assembly in a L-4B?  The 
blade has gotten out of round and slightly rubbing the back of the blade 
housing. I tried removing the set screw to slide the blade assembly 
slightly forward but can't move it on the shaft so may have to replace 
entire unit. Would appreciate details if anyone has any.

Thanks,
Garry - WR4R