The door mirrors were installed by the dealers, there likely were hundreds of different types depending on what dealer and where they were sold, most installed big ugly mirrors, find something vintage you like and install them.
What exactly is wrong with your instrument cluster?
Do you have your bench seat or at least the frame, if you have the sliders you could put them on a 620 bench seat and use that, 520/521 bench seats are the same except for maybe the seat material design.
i have a modified fork lift seat in there now that works but not the greatest thanks for info on the seats
i have a full cluster but only the fuel gause works...nothing else