Hi Mark,
You mentioning the brakes on the V8 powered D series reminded me of my mate in one, a six wheeler, belonging to S W Brisbanes of Knighton, he was on the A456 going down the hill into Bewdley (before the bypass was built ) when he came to a tailback of cars, his D series Ford, fully loaded at 24 ton failed to stop, he hit the back end of the one in front of him which caused the same to happen to another five. He finished with Brisbanes and went back to Roberts on ann Atki.
Cheers Dave.