I have a light duty Landpride 6ft rotary cutter. In hind site, I should have spent more and bought a heavy duty model. I've replaced my gear box three times, drive shafts 3 times, blades ten times and the stump jumper once. I've re welded the deck on it half a dozen times and fabricated a new rear wheel bracket for a much larger, stronger rear wheel.
When I first bought my land, I used it to clear areas that I really shouldn't have. Stuff over the top of my ROPS, small trees 2 inches thick and thicker, and just about anything I could drive over. I still do this to some extent, but nothing like I used to. Now that most of the land is cleared, it's the right cutter for maintaining the tall grass and young saplings.
It wasn't too hard to replace the stump jumper. I did stand the cutter on it's side so I could get to the top and bottom easily, and I used a cutting torch to take it all apart. Even thought it was cracked and broken, it didn't want to just come apart easily. Putting it all back together was quick and easy.
If you don't want to fix it, I would scrap it and get rid of it. I personally know that if I don't have a use for it, it will sit there for years in my way all of the time. Eventually I'll get tired of moving it to a new place that I will hope will be out of the way, only to have to move it again when it's in the way of what I want to do. After years of this game, I finally get smart and haul it to the scrap yard for a couple of bucks.