Re: Controls to use on a Mercury Mark 75A
Back in those days controls had 2 levers; one for throttle and the other the shifter. One of the problems with that design was the fact that the shift lever had no idea where the throttle lever was sitting and it was common to see people slamming their engines in gear with the throttle at a 2000 rpm's when it should be more like 700. Played ....with the drive line.
From what I know about R in those days on Mercs, you had to stop the engine, put the shifter in R and restart the engine in R whereas today, you can easily shift from F to N to R at will (when at idle rpms). Real crummy design, especially on cold mornings when you wanted to back the boat off the trailer and the engine was too cold to start in gear, much less run there.
Might try an online shopper if you can't find a local dealer (or online dealer for that matter) that has been in business for 50 years and has some parts lying around.
My 2c,
Mark