Ok outside of your radiator issues.
let me understand this. you bought a 33 yo vehicle (at the time) drove it three times, put 2K and whatever time (not including the recent heater issues) into it. I fail to see the problem here.
As a comparison. I bought mine in April for about the same price and I am up to 3K (not including mods) and I have not painted yet.
The thing about older Land Cruisers in general is this.
if you buy one, and expect to drive it immediately after buying it without any work.
1. you paid over 10K for it and everything checked out perfect
2. you checked nothing and just drove it thinking they are bulletproof (they almost are)
I have never bought any vehicle for 6K or less that did not need something right away or damn close to the end of 1 year.
Land Cruisers in general are fantastic vehicles IF they have been cared for. If not it will cost $$$ to get them back to that state.
While it seems i was lucky that mine had a rebuilt engine and new front brakes. After upgrading the suspension, i pulled off the rear brakes. They need to be done. The brake lines outside what was replaced (from the caliper to the T fitting) all need to be done as they are iffy.
Could I drive it like that? Yep. Will I? Nope.
Once you start digging, your level of comfort on what needs to be done to feel safe have a reliable vehicle, and comfy interior will vary. But will cost to somewhere at some time.
Now compare a 33yo Vehicle to a 10 yo vehicle. Your yearly maintenance could be about the same for the same purchase price.
Few years ago I bought a 2006 Yukon. After replacing all bearings in the rear diff, all new brakes, new Tie rod ends and ball joints in the first year. 2K was cheap.
So while keeping an eye on the cash spent. Realize that you are spending it to repair off the the things the PO's did not. Essentially you are doing much needed maintenance. In the end you will have the feeling of:
1. I did it myself!
2. I did it myself, right and i know it is done and when it was done. Now I am confident in my vehicle.
Sorry bit ranty there.