I couldn't resist to buy a TD 124 II

Of course, it needs TLC and progress is on its way.
At present, I got two issues:
1. The pitch control knob does not work properly. Without stepped pulley, cir clip and the felt washer, it works but it fails when felt washer and retainer clip are on. I fully cleaned the mechanism and put some grease under the eddy break. Any advice?
2 Idler wheel: I understand that there should be some kind of retainer on top of the idler wheel spindle. Mine has none and it did not come with nylon washers under the idler wheel either. There is a very thin transparent plastic ring glued onto the idler wheel holder and I have very little space between the top of the idler wheel and the metal bracket. Is this normal?
Thanks in advance for your advice. Cheers!
Bernd