Well, I did not notice the width of the rudder, probably because I did not look. But, I do have a problem with the top of the rudder where the wood block is on top. The heith or something just does not match. I cannot the smooth transition from the stab to the rear of the rudder. I kind of got it, but I do not want to grind much more off... might get into the foam..

On the baby powder... same thing goes with wet sanding. I saw a video of a guy who put some light filler on his sanding block. He sprayed the model down to do wet sanding... then went to sanding with the filler compound... it filled the cloth when it dried, and looked pretty smooth.