I'm curious about this. No way the stringers in mine are balsa. I got to poking around on some of the stringers at lunch with the threaded-end of one of those otherwise unused 2mm pushrods. I also poked on a bunch of balsa and basswood sticks I have. The stringers in mine are way harder than any balsa I have, and about the same as the softest third of the basswood sticks.
Ok everybody... start poking and report back!
Better yet, maybe a rep from Pacific Aeromodels is lurking and can fill us in. If mine are balsa, I want to buy some of that balsa!
I'm also curious if everybody's GBY has the number 0060 stamped on the inside of the fuse, next to the wing-dowl opening... or if this is a serial number? There is also a small 22 in a circle stamped next to it.