RE: Ulimate L/G - U/C for 1/2A airplanes.
On the Cheap Thrill, I had the two-wheel landing gear sandwiched in a ply-balsa-ply box which inserted into the fuselage behind the tank, and was bolted in from the tank compartment. That way it could be removed for flying over grass too long for take off.
For reed valve mouse racers flown off hard surfaces, I sandwiched a one wheel gear in the ply-ply-ply engine mounting firewall.