Part two of the experiment was to be a back-to-back test under the same conditions, but with the dual stage Boyesen fibreglass reeds. As you can see from the pics, it seems the flaps open first under low revs, with the big windows opening up under higher revs. After blipping the throttle, the response is noticeably more crisp. With hopes high, I rode back to the same spot that I managed my 30mph run, but then had the misfortune of overestimating how much fuel I had on board, so ended up pushing it back 2 miles to the nearest gas station. And that is where the experiment ended.
On the upside, my 70cc assembly is close to being ready, so I was not going to delve any further with this setup, however, Ken has piqued my interest in what that pipe might be able to achieve with proper jetting, so I am now contemplating an intermediate stage of attempting to tune the Dellorto to the 50cc setup first, to quantify the difference it makes. Once the 70cc is ready, it would then also give me an idea of whether the overall improvement is coming from the extra capacity, or the better carburetion.
So in summary, the planned evolution will probably be: Factory 50cc (24mph) --> 50cc + Pipe (30mph) --> 50cc + Pipe + Reeds (top speed TBA) --> 50cc + Pipe + Reeds + Dellorto --> 70cc + Pipe + Reeds + Dellorto.