1970's 1694 4 track reel to reel - Anyone that know the old reel to reel should be able to answer this. Both JVC and Sony made the reel to reel 4 track players that had black rubber cups on top the pins where the reels went. I want to know how to get them off - They don't seem to unscrew or pull off. I assume they have to come off before the tape goes on.