That's the one where the pipe layed beside the cab and stuck off the front and back isn't it? Did they ever make it into production?
What was the big plan for the ‘56? Drive train?
BV, the axles would have been Rockwell or Timken. That's a Westinghouse park brake assist, IIRC.
Can't read the vin plate, looks like a 825, so before 1956.
Any comment about the dual air gauges