@CursedFlames Ok.

I have a book on the RAF's major advancements, I take some sources from it in this, though these might not be 100% reliable:

• It could have been fitted to Mk 1a Spitfires. The Hispano cannon was fitted in late 1940, where Spitfires and Hurricanes were the RAF's main fighters. My source doesn't specify which variant of spitfire it was though it does say Spitfires took 2 cannon in the wing in 1941. In tests in using Hispanos for Spitfires is not completely unreasonable to assume they used Mk1a Spitfires as they would have been the dominant variant at the time.

• For your second question, yes the Spitfire Mk1a had flaps. I actually think all variants of spitfire had flaps, save perhaps the early prototypes. The flaps were split wing design, extending nearly 90 degrees judging by the look, used only for landing. There was only 1 flap setting on spitfires, controlled by a single switch.

@HistoricBirds I played Wings Of Duty and the Mk.II spitfire had 20mm cannons and the Mk.I didn't. But I think the Mk.I did have the hispano cannons.

Wanna here some Spit Facts? - Vsauce

@HistoricBirds I know some versions had split flaps. Can't confirm if all had them.

@F104Deathtrap what about flaps?

This is a cool post, but wikipedia had you covered from the beginning.

@pavthepilot