What you need is a Hohner Dronique, or something similar. With keyboard instruments, the bellows has always fed a windchest rather than a bag; although we have a small ultra-portable lap-tap style Indian Harmonium that uses the reciprocal bellows more typical of a Shruti Box - Rachel's playing it HERE. Alas there are issues that make it problematic: 1) It's fiercely loud and needs careful muting. 2) As with other Indian instruments, it's several cents sharp of concert so we can't use it with the Kaossilator, which is fixed to concert. 3) The workmanship is so bad it's a miracle neither of us have suffered serious injury from the razor sharp sheet-aluminium decorations. 4) The interface between bellows & windchest needs constant attention and maintenance, which also goes with point 1) about the muting. As a result, Rachel's more or less abandoned it and now uses guitar instead, which is all part of the Folk Process I guess, but such is the potency of this unique little organ we keep it for occasional studio & session work where concert isn't an issue, and it's perfect with my Indian pocket trumpet & military-pitch clarinets which I hope to get back in touch with once my dental bridgework is completed in the new year...