Geo, almost all cardboard kits of planes are of the 1/33 scale. I don't remind myself the reason for that but just that seems to be a kind of a compromise between a model size with all details and the costs of paperboard with printing. For instance scales of paper ships depend on the model type. e.g.. submarines,destroyers are of 1/100 or 1/200 scale typically while cruisers, battle ships and aircraft carriers of 1/200 or 1/300. The tanks are of 1/25 scale.