7.5 tonne GVW came after the 3 tonne ULW rules . i think if i remember rightly you had to prove that you had been driving an under 3 tonne unladen vehicle ( a bedford removal van in my case) for a certain amount of time , this then qualified you for the magic under 10 tonne GVW limited HGV licence . we only had caravan transporters which were all over 3 tonne ULW but on;y 8.5tonne GVW, so i got mine simply by asking one of dads mates who did have a handy bedford tk under 3 tonne ULW van to state that i had indeed been driving it for the stipulated length of time and hey presto i was off with one of the bedford tk’s ,with 33 foot long 9’6" wide mobile home aboard.
tony