vine beater vs flail mower vs stalk chopper conversion

So I have a "Speedy" brand... what my dad called a "vine beater". I've also seen similar things on ebay called a "stalk chopper"... The "blades" appear like if you cut off the last 6 inches off of a leaf spring and mounted 4 in a row on a common foot long pin through ears welded to the center shaft. The "blades" are broken and in pretty poor shape.
I have long thought about mounting u bolts with blades or scoop blades with spacers in between it. The chain is missing and I don't yet have a PTO shaft that will work.
Anybody have any input as to my plans before I get too deep? Am I going to need to change sprocket size to get a rotating speed? Better to maximize the length for the clearances I have to compensate for a slower speed? Can't find much information on the old girl, and I would sure like a flail rather than messing with brushhogs.
I'll be using mainly a JD 4020 so i doubt power will be an issue.

What are you trying to cut, and for what reason?

Flail mowers are kind of a specialty in this area, mostly just for chopping down cornstalks.

For cutting grass and weeds, we go back to the rotary brush hog deal, less power and jumps over stumps and chops up brush a lot easier. Doesn't leave standing streaks like a flail.

Neither makes good hay here, they chop it up too fine.

There are several different designs of blade on the flails, cup, J, L, and more, I don't know what is good for what.

My 5 foot brush hog is a lot cheaper to run than the 6 row stalk chopper, always chasing parts on the stalk chopper and more fuel per acre too.

Sounds like a lot of parts and cost to get something useful, so be sure it does what you want when you are done fixing it?

My 12 foot (4 row) stalk chopper was a load for my 85 hp tractor pulled it a time or two with the 60hp and that was not enough for real work, the 15 foot uses most of the 140hp I put on it in stalks. Takes less power in soft grass of course, depends what you are working it on.

Just random thoughts from a northern corn farmer, might not be helpful for what you are trying to do or for your location.

Paul

Sorry. Should have clarified. Intended use is just for trimming up trails in the woods, and maybe chopping up fallow crops to ease disking it into the soild later. It's only about 7 foot wide. With some of the blade styles I was seeing... thought I could get blades set up for maybe about 350 bucks.

cutting grass and very small brush (1/4 inch) max