Old Torchmate Router mechanism help needed

I own a TM 2X4 circ approximately 2011. I bought the router package at the time but haven't used it for years. Anyway on the router Z axis there are 2 brass pieces that allow the threaded screw to go up and down through them. I know there used to be a plastic piece that would attach to the upper brass fitting to the black piece in the picture but I lost it and think it is screwing up my z axis movement. I could make a new one if I knew the dimensions of the piece or maybe even if I understood what the function of that piece is. Anyone have the piece I am talking about?

 

Here is the picture

 

This is the backlash adjustment, just a flat piece of plastic with a post on the end that engaged into the brass piece so you could slide it in and out to adjust the lash, the screw on the black piece would lock it in place. Would be very easy to replicate.

 

thanks for that.