Please forgive me John, if I’m wrong, but I suspect that you’re getting at the fact that not only were errors in parts books through simple silly mistakes, but major errors exist due to differences between manufacturing practice and design.
You have no need for forgiveness. There are many layers to a onion and we cannot see, or understand, the whole story until all layers are peeled back.
I have little interest in whether a washer was used, or not, but with the builder's workmanship. I am more impressed with a bike builder like Dave Perewitz who's creations can be ridden daily, than a trailered "perfect" restoration.
With the current use of electronic ignitions and electric start kits I spend more time trying to make people understand that you need a good battery
, not a new one.