FDK, you might want to check out the latest 'Flight Path', which has a write-up on the CAC Turbo Boomerang, re-engined with a B17 turbo-supercharged powerplant.
The Turbo Boomerang was very favourably compared to the P51 & Spitfire by the test pilot who flew all of them at the time; was considered to be actually better in some areas. The Government of the day elected not to go to production, prefering to concentrate on licence building P51s, Beauforts & Beaufighters.