When I was a teen, Mechanix Illustrated came out with the Tri-Magnum on the cover. Every few years I go back and look at the thing and think, I could build that. However what has always stopped me is the fact that I did not have a good donor bike for the project.
Recently I bought 2 Goldwings, a 89 GL1500 and a 84 GL1200. The 1200 is nice, looks good and just needs the alternator installed, I have ridden it and it is nice.
The GL1500 is a pig, about 50% of the plastics are broken, cracked or just plain missing. The seat is shot, the chrome is bad, the windscreen is opaque and it over all is faded and looks like a turd. However, I have ridden this also and it runs and rides like a dream. I will spend twice the value of the bike replacing plastics and other parts and it will still never be anything I can sell.
So, this got me to thinking, everything that is bad about this GL1500 with be removed and thrown away in the conversion and what is left is hidden under bodywork. I would basically strip it to the very basic frame, no plastics for the build.
Having reverse is a major bonus as is cruise control.
I am thinking I may adjust the bodywork to a more open cockpit with a roll bar, kind of a 3 wheeled convertible.
Where I live we get over 200 days of sunshine a year and less than 9 inches of rain.
See here https://rqriley.com/product/tri-magnum-trike-plans/