To be honest, the engines sound great, but the clarity of the gunfire is too good from inside the cockpit in my honest opinion. The BigPickle MGFF sounds are much more spot-on in a realistic gunfire sound aspect.
RedBatFlight made a soundmod for IL-2 called "Distant Sounds Mod" and it was excellent in both realistic distance sounds and gunfire/explosions. A fusion between his gunfire sounds and your engine sounds would be a wet dream.
http://www.youtube.com/user/RedBatfl.../4/9G8xWDyGwX8
I think the distance sounds are great, also the internal gunfire and distance external gunfire sounds great
Here is a "realistic" flyby with gunfire sound:
As you can clearly hear, it's just "clapping" noises from relatively large guns (.50 cal).
The high-clarity metal clank sounds are for counter-strike, there I said it...
Heres a better attempt to re-create a real-life sound environment...
Ok, gotta fly.