Tools for encoder and encoder disk alignment
Here are some photos with metric measurements (Click to enlarge and move screen to read gauge display):
As mentioned earlier, I have not tried to align the encoder with the tool shown. But the tool fits nicely on the still connected encoder and I believe it would work if I needed it.
The U-shaped spacer (or shim) for the encoder disk is tested and works very well. It needs to be 0.134" = 3.4 mm thick.
The picture below shows the shim in use to set the correct height for the encoder disk. The two holes into which the PCB stakes of the other alignment tool would fit can also be seen. The encoder mirror gets connected by pushing it's frame into these holes.