It's done, I think.
After spending all afternoon and missing dinner, and trips to Autozone, Advance Auto Parts, and Homedepot, and two 1 1/4 hose clamps, and a bucket of sweat, it's done, I think - The oil cap now comes off. :dance:
Thank you, to Stl-986, elgyqc, itsnotanova, Gilles and ike84. If you guys are ever in NYC or upper NJ, send me a message. Lunch is on me.