Each Byron is converted by clients request, especially for the lenses they picked. Different combinations of brands and types of lens, shutter, it definitely needs each lens' infinity stop be measured specifically.
After individual measurement for each lens, then the i.stop engraving need help by my mechanist.
A special T type lathe knife was ordered.

The knife will engrave the plate a 1 mm width ditch, to keep and hold the front standard. Measurements are precised down to 0.01mm, with a CNC lathe machine, that will do the job very well.
And now my mechanist will make a fixture tooling, to hold the plate in fixed position.

Fix the plate in vertical position, and lathe tiny ditch according the measurements.
http://lh4.ggpht.com/_gvRcWa2LHhg/Sz...0/P1021169.JPG
Then the plate is engraved the focal length by the ditch, for identification. I need some more practice of engraving......

For my own reason, to ensure pairing the plate with matched camera body, I engraved each owner's name on the back of the plate.

Then the installation, and rechecked the focus. Noticed that 90mm lens distance scale at the right side? that is for un-coupled focus.