JEM Watercraft

Could someone please advise me as to the best way to mount a small outboard to a pontoon boat, like the one described in the free plans. Since there is no vertical surface like on a regular boat, I know I need to fabricate something to attach to the deck to clamp the motor on. Any ideas on how to construct this. We are talking about a 2.5hp motor. I have a motor mount here from an old Sevylor inflatable. Could I use this, and if so, what would be the best way to attach it to the pontoon boat. Thank you

A straight vertical attachment would work fine. Could attached a simple 2x6 and brace it with some simple triangles cut from plywood. I personally would make the mount from layers plywood as it's strong and more dimensionally stable.

Glue in place, fillet, and fiberglass for strength.