What if... #2

Latest Flypast has an article about the Spitfire Type 508/509 otherwise known as the T8/T9 two seat trainer.

It touched very briefly on a possible Griffon powered Mk18 low back two seater (Type 518) but nothing came of it probably due to lack of interest more than anything?

As we have a couple of MkXVIs in various forms of restoration wondered what a low back two seater (a Type 516?), would look like...