I used to run pickups which were about what you describe. For every thing that you fix, two more go wrong. There comes a time when you need to cut your losses and start over.
Myself I would rather fix equipment then operate it, but what really bugs me...is when I have to fix the SAME thing over and over. I had a bulldozer like that. It had a starting issue when I bought it, and 2 years later it had the same starting issue with it when it left. How bad could a start circuit be...stupid thing, kind of glad to see that thing leave...
Probably won't stay in gear because the tranny got full of salt water and everything rusted and got real stiff and the shift forks got bent from trying to get everything to move. If the transmission is eat up on the inside the motor may not be far behind. My suggestion would be to try and find another DK45 and use the existing one for spare parts (has to be something good left on it). The salt is bad but the silt that got in is probably even worse. I would not sell it to anybody else unless it is just in bits and pieces, some shade tree tractor dealer will get it, make it run and repaint it with Krylon and then push it off on some other poor soul.
I would suggest getting rid of it, but not for the reasons others suggest, but not that they are wrong either...
You dislike the tractor.
With wives and children it is a bit different, you cannot just get rid of them because they bug you, but with tractors, it can be like acid on a piece of steak, it just kind of eats at you. Maybe in the future the tractor is decent to own, but guaranteed even the littlest thing will bug you about it.
A guy once told me, "If you have to ask the question, you probably already know the answer."
It will be sold for scrap metal at my friend scrap yard. I don't want to inflict this on anyone.
I would say list it on Craigslist for $1500-3000 and list that it has been flooded several times, full disclosure that way and if someone wants to rebuild it or part it out, they can't say that they weren't warned.Now I know that you've said you don't want another used tractor. I also know what it's like to be on a budget! Instead of scrapping the tractor could you part it out to improve your budget? Just throwing out ideas.