1986 Sundancer Throttle only button

[ALAN GARDINER]

George (or Anybody), I spoke with you a few days ago regarding a duel control for a 1986 Sundancer. It is a quicksilver 88688A15, A16 was a closest match I could find ( I went through them one by one as you suggested). My problem is the Starboard Throttle Only Button will no longer depress. I noticed a repair kit 85882A1 but there were no details on what it contained nor would it come up on a parts number search. The exploded view did not appear to be the complete assembly?
1) How do I fix it
2) What do I need

Thanks
Al Gardiner