M201 - 1,2,3,4 tyre markings

Thanks to Andrew Bloxham (M201 no. 11476) for pointing me in the right direction on this 'mystery' and JLM for adding more detail concerning the number markings occasionally seen on  M201 tyres.
Although the numbers are on the spare tyre of the jeep shown (left), the tyre would originally have been in contact with the ground along with three others fitted to an M201 in long term storage. Every three months the wheels were turned to the next position (a quarter of a turn) to prevent a flat spot developing on the tyres. In the example photographed by JLM (right) the hand written 2 and 4 can still be clearly seen together with '83' (possibly the year of fitting?).