Here is a minor harmonica layout that I've been using for several years to play traditional music from Sweden.
The idea is that you should be able play the notes of the most common minor scales (natural, dorian, harmonic, melodic ascending and descending) in first position without overblows/-draws, you just need to use a few draw bends. I also wanted to keep the minor I-chord and the major V-chord of harmonic minor layout so that you can play tounge blocked accompaniment in the lower half of the harp.
It mixes elements of harmonic minor and circular/spiral tuning with some notes modified for improved chromaticism. It’s fully chromatic with only three overblows and has a lot of useful chords available.
Scale examples
Here I play the two bottom chords (Am and E) followed by the natural, dorian, harmonic and melodic minor scales.
Song example
Here is a traditional Swedish dance tune by a fiddler called "Hultkläppen"
To play this tune you need the minor and major sixth as well as the minor and major seventh.