Actually, the old man's firm did discover that delivering tractors by driving them 90 miles from Harwich to Kings Lynn was as quick and cheap as putting them on the back of a wagon. They may only be limited to 25mph on the roads, but they'll do it _all_ the time.
(On topic, bit. The yard at Kings Lynn was one half of the Savages works on Estuary road)
Mark Rand RTFM