Eric / javadog,
I did manage to get that cover / bearing carrier off... thank you for your help.
I do have a service manual, unfortunately it only details the springer head, not the desmo. I was able to get the cam nut off by sliding a length of steel plate (sandwiched between wooden stirring sticks) through the head, overtop of the rockers. That kept everything locked down and the nut came off easily.
I've stopped the disassembly... until I get some proper tools and a better manual. Time for a bigger tool cabinet, I think...
Again, thanks.