Hiya
Just regarding tyres, our Mog started with 20" Continental MPT 80 which have a directional lug and were quite noisy and the shoulders wore a little unevenly and may have needed rotating more than they were. No complaints on how they performed on tarmac on an old 150Hp truck.
Next up were 20" Michelin XZLs which wore less unevely, non-directional, much much quieter and again no complaints.
I think neither had directional arrows from the manufacturer on the shoulder to suggest they should be mounted either way round. The slight tractor tread V on the 80's could be mounted "backwards" if traction while reversing in mud was more important than driving forwards. But that's a bit of a maybe. The XZL's once aired down were awesome in mud (with portals, long soft coil suspension, flexy chassis, 4x4, three difflocks, amazing driving skill etc etc
)
There's a book and dvd by a German Mog expert called Gisbert Hindenach that looks at the different 20" tyres suitable for a Mog a little more technically, with a grading depending on your expected usage. It mainly covers a Mog off road in all respects, very informative.