Sure....a foam block could be carved, but I don't think it would really help because the open nose allows the air flow to go down the fuselage to cool the batteries and esc. The open nose also allows for the FPV transmitter and camera to be installed for FPV flying.
The fuselage of the plane is 2.75"x2.75"x45". A sheet of foamboard is 30". So, the full length of the foamboard is used to make the majority of the fuselage. This is used for the esc, rx, batteries, etc. The remaining 15" is a slide on piece of tubular fuselage that can be used to hold the FPV gear.
I guess I'm just not understanding what type of "finishing" you are talking about.
I do have 2.5oz of lead weights in the nose to simulate FPV gear.