he still has too much speed for the 1/2M ( more specifically, his speed will decay quicker than established M guys )
on a track, i'd offer him 12'44/26'35 ( his 5k has to be comparable to geb2 who went 12'46 with plenty of gas at the end to finish with a 54
i don't think he was quite a 26'30 guy ( 10k is new event for him - he's better at 5k ), but 26'35 intrinsic was more than enough to win the slow london 10k )
for a track
12'44/26'35 ->58'38 , 2'01'58
for a road, i'd add about 1'00 for 1/2M & 2'00 for M
so i reckon mo is currently capable of mid-59/2'04-flat, but M is just a theoretical number as he is a long way from training for a M ( similar to working out rudisha's 1500 potential - it's just theoretical )
however, you can look at the 1/2M with some confidence as he has been training for it