Thanks Morris. I was snapping pictures for my resto thread and when I lined up the rockerbox parts, the light went on regarding the assembly.
The 3/8" washer is the key. It cannot go between the thackeray washer and rockerarm because of the step in the shaft. So, it has to go on the outboard side of the thackeray washer.
Here is the picture that made it clear for me.
Then I read the posts you linked in your reply. One created a bit more confusion at first, but a re-read cleared that up.
Bottom line is what Mr. Pete said in the post I quoted is the ONLY way they will fit because of that 3/8" washer and the step on the spindle. That point is actually mentioned in one of the threads you included in your reply.
The issue of limited oil to the rockers and pushrod balls in those threads was interesting. I'm going to look over my parts to see if there are other ways to improve the oil flow thru the rocker arm/spindles.
I'll be assembling the rocker boxes tomorrow.