7.1) Item 4, Mirror Top Screw Assembly

Two top mirror assemblies are needed, looking as below:-

There are two parts to this assembly, Items 29 and 30:-

It's best to make item 30 first. Then turn down the 2mm dia spigot on item 29, reducing the diameter until it just fits in the hole drilled in item 30. When making Item 29, I actually made the 10.17 dimension a rather easier 10.5mm.

Once drilled, solder the two together using silver solder (item 79)