Kerry, no pic.
Quite likely, never seemed neat or terribly small. They range from large 4 on inspection cover, green dabs on magnet dimple, large G on top of centre casting, white squiggles like a looped cross on the sides, green and orange stripes under the leafspring mounts, all just random 'signatures' of different guys on production line or different checks of certain parts installed correctly.
Even inside the diff behind the gears often had a paint swipe, don't get caught adding the wrong colour inside the diff. Don't be that guy...