The Merry Tiller came with a B&S engine but unknown if it is original.
Our Oxford Allen Rotoscythe is easy to start and maneuver so is not heavy at all. It is the early one with the Villiers Midget engine on it. To make it easy to steer it is important not to have both wheels engaged to drive if you intend to turn around as it is like fighting a LSD diff. When on an embankment you only engage the downhill side wheel and do the turn uphill then switch the drive over.
Only other choice is a hedge trimmer on your whipper snipper, they can be set with a bend so it is easy to hold the handle but cut evenly across the ground.