http://www.auf.asn.au/scratchbuilder/beams.html
http://yarchive.net/air/plywood_construction.html
http://www.djaerotech.com/dj_askjd/d...shearwebs.html

The above links are just a couple of the many that come up when "shear web wings" or some combination is used in Google. I think there may well be some validity to the idea that shear webs at a 45 degree angle work better. In fact, plywood shear webs would appear to be even better to handle the shear loads(positive and negative)on a wing spar. We can allargue whether the grain goes vertical or horizontal or 45 degrees. Heck, centuriesearlier there were thosewho argued for a flator round earth. But in the end GPS only workedfor the round earth idea.