I don't think we have seen small aircraft made in any other scale except the CarBucket scale and
in SB/FD style.
In the distant past several artists made non-standard drawings, but I'm afraid that while I have some of these saved in my archive, they generally lack the scale bar to compare, (and are usually fictional designs anyway).
Maybe try the Juniorgeneral scale? ( www.juniorgeneral.org
Or the Franscale? (we have the 'Figurines' made to this scale - 1px/1.5cm)