From some quick, back of the envelope calculations, I think you are going to have to place the 1/48 example about 140% (142.857 excactly
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) the distance that the 1/35 example is from the front. Does that make sense?
Let's see.....
Let's place the 1/35 Huey at 50mm from the front. This means that to look all good, the 1/48 Huey should be placed at around 70mm from the front.
I don't have a two subjects of differing scales to try that with at hand, so check before you glue...of course
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Cheers,
Linz