If it was me I would just leave it as a 3 wheeler.
I have to agree.
I understand your reasoning, for converting the trike; there are many reasons to do so.
But I also collect and ride 3-wheelers, from time to time. An experienced 3-wheel rider, just likes to take one of the old machines out, and remember what it was like.
I've had machines from the Big Three companies, and in fact, I still use a Honda Big Red on the farm. It serves me well and is more maneuverable than my Quads, it is not even close. Yes, the Quads have a place too; but for getting around tight places I'll pick the 3-wheeler.
And Snowmobile people: I even have one of the early COMMUTER Industries machines, a SASQUATCH. Goggle them.
Oh, the Sasquatch uses a Comet style clutch.
I vote to keep the 3-wheeler as it was made.