A Buccaneer S.3 could carry Tornado-era systems to sea

Could Britain build a new Buccaneer batch with Tornado avionics for surviving large carriers?

Yes as a plausible Buccaneer S.3, using a carrier-suitable airframe with Tornado-era systems rather than trying to navalize the standard Tornado directly.

A Buccaneer S.3 is a credible branch if large Royal Navy carriers remain in service into the 1980s. Tornado avionics and related systems could modernize navigation, attack, and weapons integration without forcing the land aircraft's structure onto a carrier. The resulting aircraft would still need new production, refreshed tooling, and updated engines and support. It is best understood as a new naval strike variant sharing technology with Tornado rather than a simple restart of the earlier Buccaneer.