ERFs with 4MW cabs RHD & LHD

If it is true that ERF’s first Motor Panels cab had all of those forward-axle modifications, there must have been a strong incentive. The CM report says that the show vehicle was destined for Australia. In 1966, British vehicles still prevailed in that market, and Leylands had a set-back axle. Maybe ERF predicted the increase in sales of US trucks in Australia, so moved the axle forward to compete with them. Was there legislation in Oz which favoured forward axles at the time, for instance a 5 ton limit?