S Mint mark on Franklin Mint Medal

On Franklin Mint medals I am familiar with the mint marks, or at least I thought I was. I have never seen a S mint mark and was hoping that someone might know why or what the S stands for.

Medal - United Nations (Poland) - United States – Numista

Franklin Mint marks I am familiar with.

 Maybe the member added the wrong picture. 

Perhaps then that happened on this [different medal] page also - 

N#97220 

 which does have the FM mark, but somehow 

the obverse picture looks to have been made at 

a different time - or again could be the wrong picture. 

😵‍💫 

Member also added the photos of the item within the envelope to general comments. The S is visible in the images. Tried to find other examples online, but very few of these medals are for sale and most without clear images of the reverse. The ones I can see have the flying M. I inquired about the S mint mark when processing the submission and the member (@Roger Francis) had no idea about its origin.

Hello Everyone , 

I was making some researches and I found the follow ,

Double-Checking the Artist Signatures

If the "S" is not on the smooth edge of the medal but is a small letter hidden on the actual artwork/face (obverse or reverse), it is an artist's initial. The Franklin Mint employed master sculptors like Gilroy Roberts, Ernest Lauser, and several international artists who would subtly engrave their initials into the design. 

Since the "S" is on the actual reverse artwork of the medal, it is definitely the signature or initial of the master sculptor who designed that specific country's medal.Because the Medals of the Nations of the World collection contains over 130 different medals, the Franklin Mint hired several different artists to create the imagery for individual countries. 

How to Tell Which Artist It Is: Depending on how the letter is stylized and where it is located, a single "S" or a combination of letters usually points to one of the Franklin Mint's renowned staff sculptors of the 1970s. Look closely at the letter to see if it matches one of these common engravers:

• Standard Letter "S": This is often the mark of Ernest Lauser (who frequently signed his pieces with a distinct, stylized S, or sometimes EL or ELS). He was one of the Franklin Mint's most prolific internal sculptors during this exact era.
• The "S" looks like a snake or stylized squiggle: This is actually the personal mark of Gilroy Roberts, the Chief Sculptor of the Franklin Mint (and the man who designed the obverse of the U.S. Kennedy Half Dollar). His personal monogram is a highly stylized GR where the two letters twist together, often looking like a single curly "S" or an abstract musical note to the untrained eye.
• Subtle International Signatures: For a few specific countries, the Franklin Mint commissioned local native artists to sketch the design, which was then converted into a die by a staff engraver.

I hope this might help  as you also know I have a coin with JP mint mark .