Thank you, SS. Your figures narrow the options nearer to my guess of 3 to 5 ton tilt cab (T) vehicle - with a GVW of 20,000lbs probably the latter - and it does have a six (S) cylinder engine. Brakes are normal hydraulic. Once the snow melts enough to gain full access, I shall attempt the next hurdle: identifying engine size. Great response on this site. I certainly am indebted.