One-engined Ju 52 was carrying 1000 kg over 1000 km, while being powered by unsupercharged engines. Stick an 850-900 HP supercharged radial on that A/C and there it is - a no-nonsense transport that can be cheaply purchased, that sips the fuel and that will require far less of maintenance than the 3-engined siblings. Invest some thought in replacing the light alloy parts - where possible - with steel/wood/canvas while you're at it.