Our '85 Hunter 40 uses a Yacht Specialties pedestal. I suspect most of the larger Hunters (and maybe other production boats) of that era also used Yacht Specialties stuff. I suggest this so that maybe you could find what you need easier.

On ours you can see that separate 'collars' housing the engine controls and base for the binnacle compass are simply bolted onto the top. I wouldn't be at all surprised to find that the base section is the same as yours.

Hope this helps.