Well Herpa always had model railway scales in mind, being a large producer of HO (1/87) cars and trucks.
When they started their Modell-Edition series with the 1/200 jetliners, I guess they wanted to add the JU-52 but realized (?) that 1/200 was pretty small and just went down to the next notch i.e. N gauge railways 1/160.
My guess.
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BWIA West Indies 1:400 final livery MD-83; oldest liveries: Viscount, Viking, DC-3; sandy livery: A321, DC-9-30, -80, 727, 707-138, -220) 1:250 scale? No, thank you. 
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