@Bleaney - You work with what you have, not what you wish you had.
Landrover - check (twice)
Wheelbarrow - check (with horse manure)
Shovel - check (how do you think the manure gets into the wheelbarrow?)
But that and a simple OS map was ALL he needed. I recall it so clearly because he said it in such a matter-of-fact way. Not 'how horrible, someone got murdered' but 'No, no no, HERE is how you dispose of a body'.
It made me think, I can tell you.
But I know this - IF he murdered someone, he knows enough not to involve anyone else, rely on anyone else or try to be clever. A simple plan has fewer inponderables. The landies also had jerry cans of diesel (towing horse boxes does rather spoil fuel economy) so he COULD have driven from Manchester to the north of Scotland, buried the body, driven home and wouldn't end up on CCTV of a petrol station (for example).
Who looks at a wreck of an old diesel Land Rover in remote Scotland? About half of the vehicles on the road are Land Rovers. So he had even figured out that the vehicles we had offered us some unique advantages. It would look totally normal for a Land Rover to go down one of those remote tracks - it happens so often that even if seen, nobody would be able to say when if the body turned up years later...
Maybe he lived a double life? By day a suit-wearing QS at a large building company, by night a body disposal operative. Back then horses were typically bought and sold in cash so even IF the police noted unusual bank activity, he could just claimed to have sold a horse.
He clearly HAD throught it all through as we watched that TV show. Or, at least, I HOPE that was all it was.