The tank goes behind the fire wall.

The nose had a builld up motor tray. Yoa are missing the plywwod tray that holds the motor and two spruce square formers that go to each side to give suport to the motor tray. This assembly has right and down thrust.

The. Servos , rx and battery go on the cockpit area, any were according to the cg.

The cg is 25% to 30% to the length of your wing cord( measure from laeding edge to trailing edge at bottom) this number is your Mac.
Multiply the mac number times .25= your to front cg
Multiply the mac number times .30= your further aft cg

Start with cg at 25% mac, better to be nose heavy.

Will look for the plan today.

Cheers

Juan<br type="_moz" />