Here are the measurements for the Super Vega:

main body tube - 18" BT-60
body tube extension - 7" BT-60
tube coupler - JT-60C
engine mount tube - 3-3/8" BT-50
retainer tube - 2-1/8" BT-51(?)
pod tubes - 5-1/2" BT-50
dowels - 15-1/2" long, 3/16" diameter
strips - 4" long, 1/8" x 1/8"
nose cone - 8" long