I have a copy of Andorra SC12 that looks like this:

My question concerns the two parallel lines on the left-hand side of the stamp.
On the one hand, it does not look like part of any cancellation I have ever seen, yet on the other, it does not look like it is "related" to the ANDORRE overprint, as the overprinted word and the lines are not perpendicular to each other (here, I'm thinking perhaps the lines were the result of ink getting on part of the mechanism that applied the overprint).
Any ideas?
Cordially...