In response to your non functioning speed/pitch control, I had the same problem on my 1249. They both use the same speed adjustment mechanism. Take a look at the the pulley on the motor. You will see that it is a segmented pulley with a conical insert in the center top of the pulley that is topped with a ball bearing. All of of this is mounted in a metal housing with a flat top. When you change the speed/pitch control, the housing with the flat top moves up or down applying pressure or reducing pressure on the ball bearing. This up or down movement causes the conical part of the center to move up or down into the brass fingers pushing the brass fingers of the pulley further apart making the speed faster or in the opposite direction to move closer together making the speed slower. What you need to do is see if this action takes place or if the center shaft with the cone on it is frozen in place. If so until you free the center conical shaft no speed change will happen. The service manual for the 504(in German) and the 1249(German and English) are in the library and both have instructions on how to service this mechanism.
DualSpinsMyVinyl, Dynaco-PAT4 Pre Amp, VTA ST-120 Valve Amp, Dual 1219,1249, Shure M97xE JICO SAS, V15 T III JICO VN35HE, M95HE, M75ED-T2, M71, Grace F8, Technics SL7-Ortofon TM14/Shibata stylus,Heil AMT-10b spkrs, Sansui QRX3500.