I have resolved my throttle issues and here is what I did. First off, I bought the control head sold here by sailboat owners.com. It is a very well made unit, but it is not a perfect replacement for MY pedestal. I think YS-Merriman made a few changes to their pedestal over the years and my boat was built in 1986. I had to use a hole saw to take out some material to make room for my throttle control. Once that was complete, the control head works very well and I especially appreciate the throttle set screw. My old control head had the set screw, but it was buggerred up and did not work. I also took Richard's suggestion and added a cable clamp under the pedestal to add friction.
Thanks to all the contributors!