Prolly a licence-built Allison
Kidding aside, I agree that one of a kind is very special - to the point of being unique...
I'll get my coat.
Jabo
Actually I'm led to believe it is in fact an original (reconditioned of course) AM-38.
Check the video again and you'll notice the cowlings all seem accurate to the type, plus the tell tale sign is the rotation of the propeller which is the opposite to an Allison.
I stand corrected, it is indeed Allison powered, and must have an opposite handed gearbox from a P-38 or summat. Whatever, it's a beauty!
It was restored in the same facility that recently brought the Mig-3 back to life and rumour has it that the IL-2 is set to join the Fw-190 at the Flying Heritage Collection stateside.