I am pretty sure the tank commander is the driver from the Aifrix Quad and 25pdr kit.
This is, however, the last Airfix Sherman I will ever make. Having looked online for inspiration on ways to make it look better, I discovered just now historically inaccurate this kit is. The front of the tracks are too exposed, there was always at least a little mudguard, and the gun mantle is apparently wrong. I came close to buying some Italeri quick build Shermans, but I saw that the commander's hatch is closed. There was no way of opening it without some serious work on the turret. Such work is possibly beyond my skills. So I passed. I will have another look around for some more sherman kits. Anyone out there have any suggestions?
This tank commander is from the old Matchbox Stuart kit. So he has been sat in my old model box for twelve years or something. Funnily enough I can't find my Stuart anywhere though, and am unsure if I ever finished it.
I really like this Cromwell model. I will be getting more of them.