If you haven't seen the video, have a look at Kenny Roberts getting back on one for couple of demo laps...
Skills, eh? Wish I'd got into going sideways 40 or so years ago! Body's too injured to give the 100% needed to do justice to it now
I'm just about to do something similar with my DT175 as I've retired it from green-laning because it's too delicate and parts are scarce. I also blew the engine and so it needed to be bored but for some reason the aftermarket piston doesn't fit. Mine is the early 80s model which had a rather bulky and awkward looking seat. I much prefer the earlier models, which are much prettier, but I couldn't find a good one at the time, so I've decided to either fit it with a flat tracker seat unit or something like the grey bike in the 3rd pic. Wot I wanted. Wot I got. Wot I also like.