My apologies if this has been discussed before but if this -
http://navy-matters.beedall.com/masc.htm - is true the Sea King ASaC Mk7 is to run on until at least 2018, which would infer both CVFs are to be fitted for SK, with an upgrade to MASC at first refit. That’s a tricky one to cost, or apportion costs, as by then most of the cabs will be nearly 50 and may have needed a life extension programme, but on the other hand it would certainly spread the financial pain of CVF.