Actually, it is documented that the prototype 150 (an unsold 140 fuselage modified with a nosewheel, new tail and modified wing structure) was officially designated the Cessna 142... but only for a day or two. The "142" was to be built under the 140's type certificate, but the CAA soon determined that the new aircraft was different enough from the 140 to warrant a separate type certificate. The 150 designation was chosen by Cessna to differentiate between the two similar designs, and hoped this could aid sales with the introduction of an "all new" Cessna!
