Your wondering how far they travel, I also do marked "Where's George" dollar bills. Usually they travel up to 60 miles from Boston in about 60 days, but have had 3 show up in California and a couple in South Carolina, it is interesting.
I was wondering if it is worth marking the edges of 2,000 halves I am about to dump and then see if they show up again, figure edges would be faster to mark in a bunch, hold them like they are in a roll and wipe paint across them, or I could do something on the face as I check each one, and I do look at each one to see if they are a no FG or a rotated die