Homebuilt Spitfire replica

[Hobbes]

Not a 1:1 copy (he built a wooden wing, and used an Allison engine for instance), but it does look like a Spitfire:

https://www.youtube.com/watch?v=pzkoTulqA1U

[kitbasher]

Thanks for sharing, sir.  So basically he brought zenrat's USAAC Spitfire (http://www.whatifmodellers.com/index.php/topic,44986.0.html) to life - had the back story's Allison-engined version been built.

[Knightflyer]

Are the tennis balls in the exhausts a one-shot rear defence option 

[perttime]

Are the tennis balls in the exhausts a one-shot rear defence option 

I suppose they are a traditional way to keep birds and squirrels on the outside.
I've also seen cut tennis balls being used to cover sharp wing trailing edges at the wing tips of racing aircraft.