I've been reading up on mint marks and their authenticity but, the fact is I {bear with me please I'm a disaster when it comes to typing} wouldn't know if it was real or not. Up until now, I didn't have anyone that was interested.
I looked at examples of the inverted S and saw the difference in the loop sizes you noted above, I also noted in the coin above, the bottom loop was significantly smashed into a larger dimension, to my mind, wrongly, I see now, that it might have been the small ball serif and top, to me, wrongly, the top serif looked like the bugle shape. The one good thing from this post was learning about Variety Vista as a resource. So, was my post a joke?
I really should pay more attention to detail, you were asking for an inverted s and I only gave you an s. Thank you for telling me all that you found it helped me to learn a bit more myself. learning experiences are always a plus.