Found some more "parts" today. LHS just happened to have some really looong stroke air cylinders!
I will mess with these a bit and see if they work better than the electric retract servo to move the battery - massive force at 100psi!
I ran out of channels when I built my B2 and had to make compromises I didn't like. Never thought 9 channels wouldn't be enough but this project needs more as well. Sooo a new radio was in order - pretty good deal and 14 should be enough