Art,
I’d love to take credit for that idea, but saw it on the FFCobra...FFCars.com forum some 12 years ago, and copied it for my DOHC 4.6L powered roadster. I drove that car for 2-years, almost 2,000 mi always parked in the garage and never once smelled gas fumes. Yes a very simple design. 4” rotary sprinkler head with the guts removed, barbed 5/8” fitting screwed into base, activated aquarium charcoal and a 3M scuff pad to hold it in place top and bottom below the screw on cap!
We will flash out the EVAP stuff from the ECU. We have a Tatrix 2.0 cable and the RomRadier software to attempt that process...