[PeterA]

It is a Merlin

It appears to have just a single stage supercharger but has a four blade Dowty propeller and fish tail exhausts that look decidedly Spitfire.

This is not a combination generally found in production Spitfires if indeed it is a Spitfire.

It could be a very rare Spitfire Mk VI or even a Seafire III.

Further images of the structure and engine bearer would confirm.

PeterA