looks good! Just the thing for problems too small for the bigger guns. Are you going to add an ammo feed belt?
On the AH-1S Cobra, the ammo is stored in the lower forward fuselage and fed through the ammo feed belt from inside of the fuselage to the gun. You don't see much of the ammo feed belt at all. On the Monogram/Revell kit, the ammo feed belt is molded onto the gun's rotor assembly which runs from inside the turret itself. It is very crudely represented as shown in this photo. Next photo shows the real AH-1F with the M197 20mm cannon. The ammo feed belt isn't shown but you can see where it attaches to.
I do have some 1/48 .50cal ammo feed chutes I could use for the 7.62mm of the M134 minigun in 1/35 to better represent the ammo feed belt. It would be very short though. It's probably better to just keep the molded on ammo feed belt.