I'm not taking a potshot here, but what is it you really want from us?
Apart from the engine, it doesn't sound like there's anything significantly wrong with it, high beams could be as simple as blown bulbs or as serious as a bad combination switch, surface rust under the carpet is treatable, if you make the time to do it, leaking a/c, has a way of becoming expensive, it could be as simple as an O-ring leak that can be fixed with the turn of a wrench or as serious as a leaking evaporator, body panel retainers are dirt cheap.
Whether it's worth it or not is a personal decision (especially if it's a car you love), but, from what you say, you've already decided "it's not worth another engine as the rest of the trucklet is getting nasty".
What's it going to cost to repair/replace the motor? What else is about to fail? Is this a ticking time bomb sitting in your driveway?
If you scrap it what do you use for a daily drive? Do you have something else or do you need to buy a replacement? What will a replacement cost? What are the chances of the replacement being a ticking time bomb?
These are the questions I would be asking myself if I were in your position, and the only option I'm ruling out is parting it out, that requires space to store it, which I don't have and a willingness to remove the parts that people want to buy and possibly pack & ship, potentially that car will be sitting at the back of your property for another decade or so, until you get tired of seeing it and sell it for scrap (if you can).
