RE: Cessna Retracts
You are describing the type of L.G. which folds up under the belly of the fuselage, correct?
There was one of the jet manufacturers who was marketing the model gear a good 3-4 years ago for a Vought Corsair, or Crusader. They had it available separately. Can't remember if it was Century Jets, Jet Hangar or who, but saw it at Pasadena show.
'course then if used you would then have to design the whole model around the only available size.
Wm.