I always like to see plain dark yellow vehicles. They're tough to do well... excellent work on the paint tones and patina. I also like the nice mottle scheme on the 251, good airbrush control!
If I was to critique anything it would be that the dark chipping is a little heavy handed in my opinion. I like to see chips and scratches because it's realistic but they're also very easy to overdo. But again, that's only my personal opinion. You've done an excellent job overall.
Regards,
Kenneth.