I was thinking of doing the very same thing to my L so I could put lights on it. We had a Cub Cadet when I was a kid with that exact type of set up.
Then I got to thinking, why didn't those very smart people at Gravely do it in the 1st place?
I was reading an old Power vs. Drudgery & it made the wise claim that part of Gravely's success is because all the energy from the engine goes to work via direct gearing, no loss through unnecessary belts or hydraulics.
With that type of logic, it pretty easy to talk myself out of that project....
lights would now be usable as stated. I've looked at what those Gravely elec start kits go for. This would be well worth the effort if you have a donor tractor. But then again I like starter generators