I'm not sure I understand your point, Pip (thickie that I am). I only know that various note combinations (at least 3) in any scale produce chords - and that those chords and their relationships are the same in any and every key.

Thus (in the scale of any key):

1+3+5 = major
1+b3+5 = minor
1+3+5+B7 = seventh
1+b3+5+b7 = minor seventh
1+3+5+6 = sixth
1+b3+5+6 = minor sixth
1+3+5+7 = major seventh

etc...