I decided to attempt the Heinze Kegler swingarm fix. After reviewing all the info I could find - I decided to basically follow swooshdaves lead (see links below). I also decided that I would be pretty easy to make my own collars. I purchased these - McMaster-Carr - Item 2380k28. They are 1 1/8" Shaft collars. I then drilled and tapped 1/4 - 28 holes and milled a flat. 

Swooshdave used the current spindle which is set up with the flats for the MKIII and, like him, I wanted to use those to lock against. I felt this accomplished two goals - to provide a positive location for the fixing bolt to land on and, if the bolt marred the surface of the spindle it wouldn't affect the ability to remove it or damage the bushings due to a burr that would probably be created. The center point of the flats was veriifed to be 1.00" from the central bolt bore. (I actually measured this much more accurately and found the same result.)

So armed with the correct spacing I proceded to drill the frame tube.

I then test fit the spindle and collars

I did note that the right oil filter line was pretty tight up against the collar - I actually loosened the oli filter adaptor bolts to make it easier. The collar is pretty smooth so I'm not worried about abrasion, but it is something to think about.  Due to the clearances I chose to use button head bolts and no lock nuts, just Locktite.

Final assembly...

Parts needed:

Here's some links from the Commando Forum to the articles that really helped!

http://www.accessnorton.com/not-another-spindle-thread-t5978.html

http://www.accessnorton.com/mk2-mk3-swingarm-spindle-t3344.html

Here’s a link to the “Heinz Kegler Swingarm Fix” written by Alan Goldwater

http://www.nortons.dk/doc/swingarmfix.pdf