I don't buy into the Sea Tornado for several reasons;
The Sea Tornado would have had to been designed in the early 1970s when Tornado itself was developed, that puts it in the same timeframe in both design and first flights as the F-18 Hornet. The ADV began devlopment in 1976 and was only 80% common to the IDS, a navalised version would differ even more. The ADV entered service in 86 but wasn't fully debugged until after then. A marine version would perhaps not be ready until 87-89.
The design of a navalised Sea Tornado would require British design leadership and Panavia's European partners would not have had the need or desire to push this aircraft through. Given the UK/ Italian need for ADV was more pressing, and BAe's work on the ADV variant, any development of a Sea Tornado would take secondary priority.
So the government would have to make a conscious decision to develop three variants of the Tornado from the start, in fact that might have not only altered the basic design of the Tornado but would leave the UK footing the bill for developing the ADV and Sea Tornado. Would the Treasury and MoD of the late 70s and early 80s really have funded three variants at once? ADV relied on Saudi Arabian exports to recoup some costs but prospects of exports for a Sea Tornado are practically nil. Would Panavia even have gotten started had the UK pushed too far from the start for changes and a naval variant?
It's more likely the FAA, always being the cinderella service compared to the RAF, would have been told to get on with the F-4K/ Bucc and then arrange a replacement ad hoc when the Phantom fleet was too old to carry on and the replacement for CVA was still likely to be 10-15 years away. Then off the shelf would be the only answer. Re-opening and redesigning Tornado during the late 80s ore early 90s would be too late and costly. Some of BAe's small fighter projects like the P.1110 look promising but still for a solo project with no sales prospects its a non-starter. My ultra what-if would be the EAP built as a proper solo UK fighter analogous to the Rafale with a naval variant but thats not really practical either in any sense.
So its easy to see the F-4K and Bucc lasting until 1993-95, by then the end of the Cold War means 1-2 carriers chopped (assuming all three in this sceanario survive the 1975 and 1981 defence cuts), the air fleets drastically reduced, perhaps a small buy of F/A-18C and D Hornets in 1990-92. And by then the RN is looking at replacing CVA anyway so probably would stick to a joint fighter and strike-fighter F/A-18 fleet.
For a hypothetical drawing here is link a profile I did with another artist over at Shipbucket. In the thread we discussed various alternatives for replacement aircraft. Page 1 has a profile of CVA-01 with the original airwing.
http://www.shipbucket.com/forums/viewtopic.php?f=13&t=2039&start=40