Regarding the unit markings on underside of back visor: use a lightly dampened clean cotton wash cloth and wipe lightly across the unit marking (don't soak the leather). It should make it more legible to read & photograph. Photograph the marking so that you are square with the bottom edge of the back visor, in order for everyone to be able to read the marking easier, and help you decipher it.
All the Best,
Alan