Sealander 752 ?
I used to own a 86 28.5 and It was equipped with a Sealander Head, model 752. I believe Sealander is no longer in business. There was a place in fort Lauderdale that carried parts (before 1996), but don't remember the name. Steve is right, the boat is 15 years old, don't mess with the head as it's not worth the time and aggravation. They are cheap enough that you can get a brand new unit for at a low price. Good Luck