Both the flat and upright were installed on 69 models built at San Jose but pretty certain your looking for the upright style that has been reproduced for decades
Never tried (though I should) re-plating the bracket to see if you could do that without detaching from the main body. Not sure if the process would affect the Bakelite. From there I've have done and seen others do a clear epoxy clear coat. Not easy but it can improve or save some marginal ones IMHO. Have also polished the bakelite in the past also with great success
As for reproduction we use to see allot of complaints on the sites about them but its not posted as often from what I've seen. Maybe some more recent purchases can share their experiences.
Don't have one of each here to do a side by side but in general cross the board for all of them I would double check to see if the posts are the right design and threads as well as the attaching hardware for them for your time period. Of course repos will not have the date codes but almost impossible to see that once its in the car