UPDATE

I've got cores being cut on a CNC foam machine this week. He's cut stuff out for me before, and the machine holds a .005 tolerance. REally accurate stuff (he does wing work for sailplane guys)
I should have the cores in my hands later this week. Spar will be harwood with carbon caps, with a kevlar wrapping for burst prevention.
After standing on my stock blades this past weekend, I knew I could make something stiffer.

Just wanted to give you guys an update.

Thanks to Ed Jones for sending me a blade to work with!