Hi John,
They'll be there that's for certain, but sometimes they are loaded up with paint and thus that fills in the low point in each number. I've never seen one without them. Maybe rubbing across the surface with a dirty finger will reveal them. I've sometimes had to use a torch at different angles to catch them.
Anyway it would've just been nice to see them as it would add a bit of providence in a theory of mine (and a database that I'm writing) regarding the sticker that has the ID details on it and the correlation to the paint colour used on the actual mower.
Cheers,
BB.
