I had an email back from Footman James today.
"Unfortunately at the moment we do not have any underwriters that would cover a young (under 21) on an ex military vehicle. Our insurers pulled out of this line of business mid December whilst rates were reviewed and as yet we still have no definitive answer as to when the schemes will be available.
I am sorry that i could not assist you further."
Which is fair enough a very courteous reply and within a day of me asking, i would use this company.
However it seems that the underwriters who are in the business of asking a "premium" to cover a "risk" really dont want to take any risks. I cant imagine that this is anything other than making a hefty chunk of drivers :(