I have a 1997 36' Dolphin M.H. myself and I bought it new in 1997 I still have the original M.H. manual, the M.H. is Model 535 but their is not a lot of difference in the other models mainly inside coloring and the length.
Sense I first parches it I have added a list of 50 add ons.
Which I don't think you need at this point.
Cant you go back to where you parches it and ask them for the manual and if they don't have it maybe they could tell you who owned it before
you.
You could go on line to see if someone has an extra one.
Just a thought.