Also different depth side panels. '84 based have deeper panels than the '86 based models. Examples with just the rivet for the hook, but no hook are known (Same on Spiller's models). These were probably failed castings for the Fraser's model where the rivet was too short to attach the hook, so were used up on the other liveries. The Pickford's with just the rivet is much harder to find than the Spiller's version. Add to that light or darker grey roof/canopy.
This preproduction example has trial tyres, and proposed tampo printed rear canopy. This was, of course, rejected. Other prepro examples had white roof inserts.