[SCOTI]

I'll follow up on my previous statement & the "why"..... If you paid $800 for it, can sell it for @ least that, AND only have $1k invested . . …. You learned a valuable lesson in life for only $200. If you can clean it up enough to get that $1k or more, your doing even better.

The lesson of course is don't impulse buy unless you have resources to overcome possible outcomes that don't go your way.

Me personally? I CAN do most basic to moderate vehicle wiring because I taught myself by working on stuff, comparing to/looking @ how other similar vehicles were done, & asking questions when/where possible. But, I learned over time because I kept @ it. You can as well, but IT TAKES TIME (years). This being said, I still personally avoid any potential purchase that has a hacked together wiring mess unless my plan is to rip it out & start fresh. This is typically what kills many potential purchases for me. I take a look @ the vehicle wiring & what shape it's in. I look for hacks, splices, or loose wires (in the engine compartment & under the dash). If I see a mess, I usually just walk away (unless I can get it for almost nothing) because of the amount of effort/investment/resources it will take to make it right.

I have a potential C10 that I'm currently negotiating on. His number & mine are worlds apart because he feels (& his sales pitch is) that it ("this classic") only needs this or that fixed & it's good to go. The reality is the vehicle can't/won't run because the wiring is a mess. I told him this. I said if anyone pays him what he thinks it's worth, they are either getting it for parts that specifically match a certain need, the VIN, or really like to gamble. But, they would not be buying it because it's just a couple wires away from running & driving.

You're taking on a wiring issue @ that level & getting dog-piled beyond it.
That sweet smell you described once it warms up? That's probably antifreeze. But, where is the smell coming from? Heater core leak? Radiator leak? Or worse, a head gasket?
The non-functional gauges? That could be hiding other possible issues.
The transmission slipping? No need to say much here....

Anything can be rebuilt or fixed. But, based on your situation, I would get out while you can & cut your potential losses. If you were in the DFW area, I would offer to help you choose the right vehicle based on your situation. Perhaps you can find another board member in/around your area that would possibly do the same? It makes a truck lover feel great inside to help the next generation get started!