i've heard you use the bouzouki before,
even tho it's typically a greek instrument,
i think any strings on anything, lends itself to any style, with the right touch.
hearing celtic with bouzouki, is a bit weird for me ( i used to play in a greek band! ) but i think it totally works.
this is a bit of a mindless round and round,
but it's quite pleasant.
maybe take the best little pieces of the entire jam,
and put it together with a lyric in a proper song format,
and you will have dialed it in with this grouping of instruments