Admittedly previous CAX route attempts have failed miserably, the one I recall was EuroAir Budgies LHR/CAX/DND, and although times have changed whereas more people are travelling by air it is because fares have dropped with the low-cost carrier concept and let it not be missed that Stobart Air already have a relationship with one such low cost carrier so perhaps there may be discussions going on behind the scenes.
But as far as scheduled services are concerned, and having seen VLM already mentioned, I was going to suggest that VLM may be the ideal operator, there can't be much depreciation left to go on F50's thus the operating costs shall be less, but then an operator isn't likely to fill anything like 50 seats in/out of CAX, what with BA offering a LHR service out of NCL, MAN with all it's international services not so far away and with PIK suffering financially for decades just how much of a market does CAX really have?
Perhaps CAX may become like a NWI, NWI has STN not so far down the road, has a relatively sparse catchment area, yet has IT operations, trouble is likely to be finding the appropriate size of scheduled services aircraft whereas load factors shall be profitable whilst able to compete on fares with the not so far away opposition.
But I recall reading that PIK has been making a few bob out of the military popping in for refuels, that CAX seems to have a resident GA market, perhaps the airport may be able to break even or better, I shall be watching with interest.