It was possible to do this by modifying the Miles Aerovan, which had a conveniently podded fuselage largely independent of the boom that then carried the tail.
[2] The beam aft of the pod was unchanged, bearing the same tail unit with three fins, one central and two as endplates.
[3] The taper on the horizontal tail was carried by the trailing edge, which had unbalanced elevators with trim tabs.
Since in the M.68 the equivalent section might not be present, a different layout was required and the M.68 used long fixed rearward sloping legs passing upwards through the inner engine cowlings.
[1][4] The fixed nose wheel was also different, being a little shorter and castored; the overall undercarriage arrangement placed the bottom of the container close to the ground.