There is a 2008 PPrune thread about the planned building of a replica - much secrecy but they apparently had the correct engines. The project website is:
Team Merlin - Projects - Imperial 42 - Page 1
It all seems to have gone very quiet for some years and an e-mail request, some time ago, for an update was unanswered so it may have come to a grinding halt...! Unless, of course, it has been quietly building up to a spectacular first flight from 'an airfield somewhere in Britain'!
DS