It may be that blocking the second set of reeds is the easiest approach to modding, perhaps even widening the reeds to get a bit more area. However, with an extra set of reeds sitting in that engine just waiting for someone to figure out how to make use of them, Crikey, I can't get them out of my mind.
Like you said, if the first set of reeds feeds the second, then the reeds are in SERIES and will cause a greater restriction to flow. What we need is to have the reeds running in PARALLEL so there is less restriction. Your comment about having a separate feed for the secondary reeds is what needs to be done.
I don't have one of these engines sitting in my lap to mull over, so I'm left with abstract ideas that might not even be close to what is workable. Here's the way I envisioned a possible set-up. There is that 'soap dish' contraption under the reeds. Perhaps all that can be removed and a simple plate put under the primary reeds to feed the cylinder. Then the space under the plate could be used as a channel to feed fresh air to the reeds on the case.
Once we can figure out a separate feed of fresh air for the secondary reeds, the mod should come together fairly easy.
