ok z lets get you some more usefull info.
58-64 bikes had fixed timing.
this is a pic of a stockish L62-64 mag mounting. i dont think nyloc is correct, i think its a nut and lockwasher.
what you have is one of the later (65-69) 'movable' mounts.
that said lets go over mags and mounts so you have a working knowledge.
better yet
http://xlforum.net/vbportal/forums/showpost.php?p=3681144&postcount=233
on this linked post you will see the parent thread link in the upper right.
read post 233 to post 253.
bikes that were factory equipped with movable mounts (65-69) had the movement controlled by the left twist grip.
the fact that the arm is brazed to the lower mag housing is a sign of desperation. its not how it should be done
a handgrip controlled timing setting is very user friendly.
all my bikes are set up with it regardless of year.
i wont own a fixed timing bike.