I know that this may sound a little "redneck" but I am leaning pretty strongly towards the tractor paint after all.
Keep in mind, this is for a work / local / rural driver that hauls some scrap and sees some rough usage.
Here is why:
I can get a whole gallon for $30, hardner, primer, a little bondo etc. all for an even $100 including paint. That gives me enough paint to get the flat bed painted, the whole truck and a real good start on my car trailer.
If I scratch it, I can get matching cans to shoot it for $6 each.
The truck is something I am intending to use for a couple of years and then retire to snowplow duty. It will also be shot outside, likely by high school students.....
Final thoughts? Flawed logic? Concerns?
I will say that I am going to buy a spray can of it and paint something to compare to the inside and then make up my mind for sure.
ROB