Bill - the 66 was a figure plucked from the sky as a suggested minimum for the number of mil pers in the SARF post 2012 that would be needed to man the Falklands and provide some (theoretical) transfer of skills from SAR to SH. Unfortunately the minimum, due to some crap staff work and poor decision making, suddenly became the maximum and no-one has had the balls to change it. All the bidders wanted more mil in the mix because it made things easier but once SARH had chosen its path there was no turning back.
There will be very few of the present SARF who will join their bretheren on expeditionary ops because most of them will be required to leave and transfer to SARH or remain in the mil within SARH or the whole system won't get off the ground.
I think most will opt for the transfer option just because of the shabby way we are being treated by the MoD - forced down to 4 crews per flight (because some 2/3 stars didn't understand how our shifts worked and thought they could spread the pain of undermanning) just as the EU working time directive shows that to run 24/7 SAR you need over 5 crews (and that's without including any extra duties/tasks/dets).
The fact is that the military have about 64 pilots 32 winch/radops and 32 winchmen currently employed in front-line SAR (8 flights, 6 RAF, 2 RN at 4 crews per flt) - that's 128 total.
Post 2012 the SARF will need 12 flts x 5 crews (minimum) which is 120 pilots, 60 radop/winchops and 60 winchmen = 240.
Take away the present CG crews (4 flts x 5 crews = 40 pilots, 16 radop/winchops and 16 winchmen) leaves you 80 pilots, 44 radops/winchops and 44 winchmen short.
The 66 mil pers remaining will probably be about 4 flts worth - similar in number to the present CG contingent so you will still be short of about 4 flts worth of trained personnel. There is only one place that experience and skill level can come from and that is from the present mil SARF.