I have had a look at the number of vehicles Jaguar produced with the XK6 engine, in all its various guises, and it is a formidable list. Imagine being able to buy a "power unit" from Jaguar (albeit at a price that would make your eyes water), the fit it, either yourself or have a specialist restorer do it, and your classic is brought into the 21st Century.
Now I appreciate that most classic owners want the original engine, but as the man from Jaguar says, in a future when petrol is not available (or use of ICE may even be illegal!), this is a brilliant solution.
Maybe other marques may follow suit. Those with large engines that remained unchanged for a long time. Rolls/Bentley, Mercedes, Ford(!). The list goes on.
Some XK6 fitted Jaguars.
XK120
D Type
Mk 2
Daimler Sovereign
and my all time favourite Jaguar - the MkVII.