1993 4Runner Roof Rack Parts

I am trying to locate the Left Hand roof rack mount for a 1993 Toyota 4Runner. This the piece that holds one of the main cross bars and has a tensioning knob to allow the rack to slide forwards or backwards in it's track. I have tried the local dealers to no avail. as the part is too old. This part also seems to be the same on 1994 4Runners. Live in the LA area, so anything in tthe vicinty would be great.