[djski]

The RCA's of that time period were made by Hitachi.

Two items come to mind giving a tape take up problem. The take up or reel idler could be worn and I have run into some occasions where the cassette tray assembly has a slight bend to it. That places a larger load on the reels. That can affect the supply or take up reel depending on which side the carriage is bent. Obviously your problem is with the take up reel table. Try several tapes because a bad tape can also cause that.