Thanks for all the replies!
Just talked to a sandblasting outfit that will hit everything, inside and out, trailer, cook chamber, cooking grates, drip pan, chimney, firebox - everything, for $180.
I paid $1,900 (which I now think was a little high given what I've found underneath the grease), but after a gallon of high temp paint it will all be my labor from here on (will start saving those bacon drippin's!), so still coming out way ahead over a new unit.
And, I get a three day weekend to get it in shape!
Any thoughts on applying high temp paint in high teens / low 20's temps? Should be sunny at least.