Since the last update I drilled the rear CR for the four 24mm mounts, drilled the rear CR's for motor retention and an eyebolt, found misc tubing suitable for the ejection piston and started filling spirals on the lower body. Where this leaves me is needing to finalize the fin extensions. I figured out what I thought would be a good source for square clear plastic tubing - old style towel holders. I say old because it appears these aren't in style and are not available. I even checked the Habitat for Humanity Re-Store. Actually, even if they were available, I'd have to buy the whole rack. These are not expensive when you think about a bathroom upgrade but are a fortune when you're building an el-cheapo rocket. So, it's back to the drawing board (or the junk pile, as the case may be). I really miss Reed Plastics and their leftovers pile.
Update: McMaster of course has suitable stuff...around $25 + tax, title, and license. I'll continue scrounging.