I also have one of these, I have a Thunder tiger 46 up front. It take the full length of the runway to get it to lift other that that its great to fly. You were right about the spiner mine flew off on the second flight just after it was started so it now has a Aluminium one. I also need to finish it and that means putting on the cowl. I always have a flight or two before the cowl is fitted to any aircraft.
Now that I have this fantastic looking aircraft in the air,I am about to see if I can find a plan for the Flying Models Crusader (june 1970) this also was a great looking model. same type of placement of the motor .
Enjoyed the read of the thread and it was great to read positive reports. Yours Down under Paul T.