Well, here's the weekend update....I R&Red the main underdash wire harness, after installing the turn signal goodies(minus the canceller).
The plastic canceller mounts just fine to the rear of the wheel, but it does not seat over the shaft. I figured I'll just have to live without the canceller for the time being. Then, the next problem reared it's ugly head. The new cam mechanism also appears to be incorrect, although it appears identical to the old one I took out. After assembling into the top of the column there doesnt seem to be a way to keep the coiled end of the switch cable attached to the little arm that the cam moves back and forth to tug on the switch slide. When you pull on the lever, the little actuator arm will..1) pop out of the back side of the cam, causing some slack that..2) allows the coiled end of cable to slip off. I've taken this apart, and reassembled it about twenty times, and I'm not getting any closer. Using needle nose pliers, and slightly adjusting the actuator arm, yields no success, and only makes matters worse by changing the geometry of the whole deal so that the switch lever no longer lines up with the cam, and cannot be screwed back in thru the side of the column. At wits end, I guess I'll be living without turn signals as well.