Showboat reordered this issue in grey many times. I have no idea either why the one green insert. I remember when they were in play & I would go through to find them. They are scarcer but were in use for years & most are quite worn. This is the nicest I have ever seen.
This with 3 red was issued in C&J mold too. I list many variants in my price guide & have them in my collection of $1's.