(At least until spring): I visited a friend at his marina and told him all about my wonderful project. I had decided to go without the foil and built a dandy drum from pipe flanges, pvc, u-bolt, etc. It worked, but getting the angle for the furling line to feed without tangling was a problem.
As I explained this to my pal, he said, "Oh. I've got a couple of extra drums. Want one?" After I picked my up jaw up from the ground, we opened his enormous dock
box and dug through Tupperware crates until he came up with a gorgeous, Code 0 drum; complete with line! It's in perfect, smooth running condition. It's very wide, which makes pulling the line effortless, and it has an arm coming off of it that feeds the line efficiently onto the spool at all angles.
I took it to my boat, attached the bottom of it to the deck shackle just aft of the forestay, attached the foot of the sail to the top of the drum, and hoisted it. I put a collar above my halyard snap shackle to keep the halyard itself still while the shackle spins with the sail. It's freakin' perfect!! Works very, very well!!
I will get a beefier halyard shackle (looking for an actual furler
top in the used marketplace). So far I have no complaints about this rig. I know these "Code 0" rigs aren't meant to use half furled. But I can drop the sail when it's furled and it lays elegantly on the deck like an anaconda and I still have the forestay available for any of my other four hank-on sails
that I may want to use.
So, for now, case closed. I've saved my two DIY rollers, the sections of foil that I didn't lose to the lake, and my plans. I have a McVay Falcon 16' in the driveway on a trailer and I will use the pvc rig for it.
Thanks to one and all who responded. I still think the pvc thing would have worked once I ironed out the details. I'll let you know how it does on the Falcon.