From a commercial point of view I would think it's a non-starter; most UK regions have Special Care Baby Units (SCBUs), and would only need long-distance transfer if there were no vacancies in that area.
Moreover, once a baby is stabilised for transfer, there would be little, if any, advantage in an airborne medevac; most would go by road with a police escort. Should they require urgent specialist treatment, say at GOSH, again, they would not be moved until they were fit (read stable enough) for the journey. Depending on the condition, flying could also be the unhealthier of the two modes of transport (in terms of altitude, stress, etc.)
I know of one company that provides 'private' medical flights, mainly in transporting transplant teams it must be said, and they are very quiet at the moment. I therefore think your target of 700 hours would be unachievable.
Hope this helps