Screen for the belt.... I'll give that some thought. I got all 3 of my tow-behind sycle bar mowers from farmers who had them just laying around in the weeds. No cost, just had to haul them away. None would roll, 2 didn't have tires or wheels, but they had what I needed.
I cut one down and changed the frame to make it a 3- point instead of a tow behind that works great for mowing cattails near the waters edge out to 7 feet.
Keep working on your ideas, I'm sure you will come up with just what you need.
Dan