The Option taken before TSR.2 chop was for 50xF-111A standard. That was all that DoD could submit in early-April,1965; that price came through very late at night, 5/4/65, to permit TSR.2 chop in Chancellor Callaghan's Budget the next day. Fixed price in $ on 10-year deferred terms. So was the entire package (inc. F-4M/C-130K). Offset was to be negotiated on the basis of lots of it and of high tech. Most of that survived F-111K chop, except HP's C-10A Jetstream, which was beeched.
On the afternoon of 6/4/65 an ITP was telexed to RR for initial installation development of a reheated Spey for F-111K. UK industry clamoured to migrate TSR.2 kit into F-111K, and to bid for chunks of structure, matching what MoA/Jenkins was even then securing on F-4K/M, C-130K. Treasury conceded inventory-commonality - so, standard UK radio on C-130K, but fiercely resisted any make-work, because DoD fixed prices/fixed delivery dates carried penalties for delay - both ways. So, if a Scottish Avn. fuselage panel for a C-130K arrived late in Marietta, such as to disrupt USAF deliveries, all the vaults of the Bank of England could not have met the bill. And UK's fixed price would be destroyed. The equipment fit listed by JFCF is in part a wish-list: I am unaware of any effort to fit TSR.2's IN (itself Westinghouse-derived) and wonder whether you have picked up that Ferranti would have been UK Sister Firm responsible for In Service Support of bog-US-standard? The 2 T.1s assembled by chop, standard F-111A structure, were reduced to produce, some $-credit factored back into cancellation charges. I doubt we had committed to any unproven, unpriced FB-111A feature - timing (first flight 7/67) did not match. Might optimists have been mooting an S.3 vice/as well as UKVG?
10xT.1 were ordered 22/2/66 with TF.30; 40xS.2 were ordered 1/2/67 with Spey. It has been stated that Coningsby would have been OCU*, Honington Main Base, Indian Ocean Forward Operating Bases on detached duty. The sole task of S.2 was to dissuade India from developing its own Bomb. It never had a NATO role. One reason is that F-4M came with B43, thus liberating overstretched AWRE to build Polaris' warheads on time. F-111K would need WE177 (A or B, dependent on what targets people thought they might find in the Burmese jungle: the Task was to disrupt PLA invaders, doubtless on bicycles), and that would have been a fun integration exercise.
By chop, 16/1/68 I do not know what Buy-Off-in-US standard had been defined, and suspect it was still WIP: clearly UK radio would be fitted in UK; clearly Flight Test of UK recce would be by GD/Ft.Worth, operational fitment in UK. I presume, but do not know, that BAC/Warton would have been UK Sister Firm, with duties comparable to those at HSAL/Holme on F-4K/M. I also suspect that, even if UK's £ problem had been resolved such that general East of Suez withdrawal had been deferred till the next crisis, F-111K would have lapsed as soon as it became evident that India was ignoring Non-Proliferation notions. This machine, delivered to Nellis 10/67, was becoming grotesquely expensive to own - that is why McNamara's intent for 3,000 - a prime factor in UK tagging on 50 of a proven standard product - would emerge closer to 300.
(*amended, 1725, 8/10/12: though after CVA-01 chop, and cascades of Buccs/Phantoms littering Lincolnshire, maybe Hon. would have been OCU+Main Base. I think I recall Hon. as site for the Link-Miles sim).