I think perhaps you are getting a little confused powerrabbit.
The grey version with orange interior was the first one, followed by the mid blue one with white interior and the 'tilt'. The tilt itself was odd because it simulated the full canvas roof which was only ever used on military variants of the real thing, but Britains never used it on their army Land Rover. Real civilian Land Rovers either had a truck cab and canvas tilt over the rear load platform, or a full hard top.
There are only the 3 main versions of the Britains farm LWB Land Rover, but there are a number of variations.
Just to clarify things a little:
1. Introduced in 1968 as 9676, the grey version usually had an orange interior (although it is also known with white). It came in a sleeve and plinth box, and included a small sheet of stick on decals so that it could be liveried as 'Britains Farm', 'Britains Zoo', or 'WLB Construction Co Ltd'. It had thick glazing and rear torsion spring suspension, with the front axle being fitted with a single, central compression spring. Lights were a one piece moulding which protruded from behind through holes in the casting.
2. At the same time, a set (9575) was issued with the single axle horse box. The model was the identical, but did not have the decal sheet - the 'horseshoe' decal was already fitted to the doors.
3. There exist a transition version which has the 1971 casting revisions, but is grey with an orange interior.
4. In 1971, the casting was revised and refined - the window frames of both windscreen and doors were slimmed down and thinner clear plastic card was used for the windows. The lights were now seperate soft plastic (possibly soft PVC) with a drop of paint on the rear and inserted into the holes in the casting from the outside. (these were often a loose fit and consequently were easily lost). The suspension was altered to have a small compression spring at each wheel.
The orangey brown plastic canopy representing a full canvas tilt was fitted to this version. A new driver was also fitted. He had a moveable right arm that clipped to the steering wheel, and a fixed left arm reching for the gear lever.
The model came in one of the new 'straw' window boxes. The standard colour was blue with a white interior, but examples exist with olive brown and also metallic blue bodywork.
5. The version with the horse box was similarly revised, but retained the same catalogue number (and box), and did not gain the canopy at this stage. Its colour also changed to blue with a white interior, although some have been seen with the orange interior (probably transition models).
6. Late on the life of the LWB series II model, the horse box set gained the plastic canopy (I think we can assume from catalogue evidence that this was probably late 1973/1974). At this point it also went into a 'straw' box to match the rest of the range. This later version is also known in the olive brown colour.
Also in 1972/73, the registration number was changed from MAC 68F to MAC 68L. (just out of interest, at the same time the reg no on the Dumper[9670] was changed from KCB 68F to KCB 68L)
When you take into account the different models britains have produced (series II, III, Defender 90, Discovery, Freelander, Range Rover; together with the different versions that have been produced of some (farm, zoo, army, police, rally etc, together with different colours), there are probably in excess of at least 80 Britains Land Rover Models. I haven't actually counted!!!!