After the war, then? According to my research, during the war, the Merlins powered both the British Spitfire and the American P-51 Mustang.
Yes, you are correct.The BMW plant that made the german engines was destroyed in the bombings so the spanish went to RR which had a limitless supply of engines post war.The plane had some really evil landing tendancies due to the narrow landing gear.But what the hell when it flew it was a sight to see.Go to youtube and type in BF-109 and watch a couple of rebuilt examples fly.Most impressive to say the least.