I've never seen one, but might be able to figure it out (or find someone who can) - do you have a pic?

Thanks Komi...I looked at it again to see about shooting them...but, the postmarks are conveniently partial, and the only thing which may or may not indicate a date is marked with a stamp where the characters again are partial and/or obliterated.

Unlike us, they don't have to date their customs slips...which is stinky. Really stinky.

are you sure it's illegible? What might look like scratch marks to you might be 80% of a character? (okay, long shot, but making sure....)

Naw, the problem is that it is very faint, the different strokes didn't take all the ink, and my black light isn't functioning.

can you put some tracing paper (some white parchment paper may work) over it and trace where the lines should be?