Should have omitted the 7 note restriction.That should make life easy! OK assumptions:
7 notes and never semitone followed by semitone. Twice the number of tones plus the number of semitones (seats!Ironed - predictive text!) must add to 12. Modes are not new scales then
TTTTTT whole tone
If I count modes whole tone has 1, major has 7, altered has 7 and diminished has 2. If I play each scale through 2 octaves I get to play all the modes too. Did I miss anything?