OK squid1, here we go:

It takes some time to do the flightcheck for right thrust.

First all controlsurfaces need to be straight and zeroed especially the rudder. Fly the plane under power straight up vertical. If you have unlimited power use less than full throttle. You want to have the plane to stop the upward movement after some way up.
It's not that important in the beginning in what direction the plane is falling with zero speed. You want to check the upline. With still upward vector, if the plane is turning right - too much right thrust, if its turning to the left - too less right thrust.

Important: The vertical stab has to be glued in straight, rudder trim center and you checked that the weight distribution around the longitudinal axis is even. To check this on the bench, support the rudder, lift the plane at the spinner until the maingear is off the bench. The wings should stay level. If one wing is dropping add lead to the other wing until OK.

I can tell you, you need a lot of uplines because wind is always a factor. I check this in the morning at our field when there is no wind whatsoever and nobody around. It's kinda boring also for the clubfellows.

Chuck