The fitted slider has a diameter of 12mm and length of 12cm, it is latched directly to the shackle using M5 screws filed to 4.5mm. The track slot is 5mm. The track itself is around 12.7mm diameter or half inch. The precise measurement is difficult.

 The bottom slider has a wood handle to sandpaper the track. The top black slider is the original plastic coated slider which jammed. The VHF bracket is on the left. The red container is Swiss cow milking grease, it could be a good replacement for McLube.