Put the servos near the rear of the radio compartment. That will give you room to slide the tank back and add a smaller tank for oil where the fuel tank would normally be.

There is an open area on the bottom of the nose just forward of the landing gear. Instead of sheeting this area, create a hatch there. It is the perfect place to store the smoke pump.

Here's a vid of my Skybolt with smoke:

http://www.minnartist.com/RCU/grafix...t_high_res.wmv