key signatures and the dulcimer tunings (and/or capo placements) necessary to play them

I regularly run into the problem of finding a songI like in an old hymnal, etc. having a different configuration of flats/sharps in the key signature thanI am used to, and not knowing how to tune my dulcimer to give me the correct notes necessary to play it! (I have 6 1/2 and 13 1/2 frets, but no 1 1/2 fret.)

Can anyone point me to a source that lists all of the possible dulcimer tunings (DAD, DAA, CGC, etc., etc.) and for each the key signatures that are playable when in that tuning? Also, the additional key signatures that are attainable when placing a capo at various frets within the tuning?

Right now I am puzzling over how to tune to play a song having 3 flats in the key signature (A, B, and E - I think that makes it the key ofE flat major?). I don't want to transpose, as that result changes the "emotional color" of the song compared with its original tuning. Please help . . . many thanks!!