Thanks for the replies chaps.
The difficulty is that he is helping us free of charge. Its a charity project and he is doing this out of the goodnes of his heart.
We are not employing him as such.
Although a civvy, i have a lot of experience with the military and have worked a lot with the mainly the RN - and other navies. I could have a decent stab at spotting a Walt if he was ex-navy.
He's ex AAC. Recent Ex as in Telic