While I'm all for a bit of "tinkering", why make a molle bandoleer when there's already a few on the market, some of which are fairly cheap but still well made, & as for the back, well just get two & put them together ?.
Personally, I love the bandoleers, been using them for years, got 3 I think?, & knowing how much stitchwork goes in to them, I'd never try to make one, not a cost effective use of time & materials.