Dale,
You need a break. Take the cruise. If you're like a lot of us you'll have the brakes figured out in your head by the time you return.
My technique for installing the pin and clip is pretty simple. I use a pair of fence pliers I used to make my living with. The nearest thing I find in stores now are linemans pliers. They are heavey duty, square nosed with wire cutters on the sides of the jaws right near the pivot. The handles are about 8 inches long. You can cut a 10 penney nail with those cutters. No tool box should be without a pair.
Push the clip into place. Feed the pin in from the back side of the backing plate. Line up the flat on the pin with the slot in the clip. Hold the pin in position. Align the nose of the pliers with the slot in the clip and the flat on the pin. Have the pliers open a little so the pin will go in between the jaws. Use the linemans pliers to push the clip inward enough that you can grab the flat on the pin. Twist the pin 90 degrees and it's done.
One or two more comments. My first car was a 69 MGB. My first trip in the car was to the tool department at Sears. Everything I know about working on cars came from doing the work myself. When I was younger I had more of whatever it takes to learn this stuff and not get as frustrated. Maybe it was due to the fact that if I didn't fix the car, I didn't have transportation to work.
My neighbors think I'm an idiot for working on my cars. "Pay someone", "Don't mess with it if it ain't broken" "Wal-Mart will change your oil"... Although it's frustrating at times I still enjoy the results.
Your affair with the TR6 got off to a rough start, but you've learned a tremendous amount. Who was it that asked if someone stole your avitar? Something about removing the differential? The bottom line is eat the elephant one bite at a time. Enjoy your successes and ask for help when you need it. Oh yea, if you send the car to the crusher we're all going come there and burn PR to the ground, take away your birthday and give you a girls name (after we plunder the rum distilleries!)