fledermaus

Since older plans were hand-drawn, there was a good likelihood of errors creeping in. Thus, left and right wings might well not be identical if a measurement error was made in drawing one of them. It's a case of "builder beware" I guess - measure twice and cut once and all that.

Nowadays with CAD you can still get mistakes, but usually left and right wings or stabilizers will be drawn by duplicating and mirroring so at least that fault is less likely.