Man, I'm not finding these either. I've tried both online and local. Home Depot, Lowe's, Ace, Tru-Value. Nothing. Found one on Ebay that looked right. Cost $10 so I thought it must be the old style (new ones go for less than $4 EVERYWHERE)....nope, pyramid.
I even bought a bunch of balsa in hopes of carving one up. Decided my skills are too weak for that, given the curves and radii and whatnot.
Hopefully someone can come up with another option....soon!!!