I had to go to Victorian Outboard Wreckers for a replacement trim ram housing for my 1994 120Hp. It's a fair hike getting there but it got my hydraulic problems sorted. Now I've got new problems but anyway, they're in Seaford, down on the Peninsula. They have plenty of old Chrysler motors there that they strip parts off. Apart from being white in colour. Most parts are (almost) identical.
i think 1991 still mounted the trim pump directly to side of bracket with three bolts in a triangular pattern. They should be about halfway up the bracket. If you have the triangular pump mounting then Chrysler brackets should be interchangeable. Just pay attention to steering tube as some old chryslers did not have one.