Behold, the smallest copy of Wild Gunman you are likely to ever find. About one-tenth the size of the regular cart:
I just picked up a set of Famicom erasers and this was by far the smallest one in the lot. Back in the 80s collecting erasers was pretty big with kids here in Japan. Actually I remember it was big in Canada too, in the 3rd grade way back in 1984 I had a few cherished erasers shaped like various things that I kept in my desk at school.
Here you could get them out of those Gachopon vending machines. Wild Gunma here is so small that the eraser is basically just a generic rectangle that looks nothing like a Wild Gunman cart:
The larger ones though look pretty cool and the erasers themselves are miniature versions of the cart, like Dig Dug here (next to a regular Famicom cart for scale):
I got about a dozen or so of these in the lot, they are all games released early in the Famicom`s life so I think these probably came out in 1985 or 86 at the latest. A very neat little thing that I will never ever in a million years be using to actually erase anything.