I had my Albert swan neck mirrors re-chromed and when they have come back they were in bits and I must be hopeless at doing a jigsaw as I just cannot work out how to reconnect mirror part to the arm. I asked the chromer and he said that it was months ago an staff have changed so cannot help. I've tried searching for some drawings or instructions on the net but come up empty. Interesting thing is when apart some internal parts like spring and a cap of some description are different.
I'll take some pics and post up but hoping someone has a mirror that may be able to help.

You can see the different springs and the cups are a different size


you cant fit head of arm through mirror nor can you remove bolt, you can on one remove the nut the other looks like its broken off.