Wanted - used LK 550 mixing valve for parts

jalars8

I am looking for a used LK 550 mixing valve to use some of the internal parts to hopefully restore my LK 550 to function.  Specifically, I need the piston (or pin) that would be in the top of the thermostatic element and the black plastic part that is located immediately below the black cap and which screws down into the brass valve body.