I wonder.. I'd gut the 30mm out of the 410s, the 13mm from the G6s, and the G2s engine.
Mod the E4 with 2x13mm in the nose and a 30mm in the Hub.
Retractable tail wheel.
Remove the MGFFs and smooth out the bumps, increasing roll rate.
Replace the canopy with curved plexi to have it Yak3 style but retaining the razorback, adding mirrors to the canopy ring.
Replace the spring loaded slats with 262 style ball bearing slats (which are not on the AH 262

)
Replace the 3 blade for a Spit14 style 5 blade prop
Worried about weight I'd adjust the ammo loads 500x13mm and 40x30mm, lower the power output to match a 3bladed; improving fuel efficiency so I could carry less fuel.
Keep it no more than 6400lb at full fuel.