Leather Coat

[Cwrenn]

I purchased a grouping of old German uniforms and this leather coat was included. It's obviously been worn (extensively). It has a really nice/heave removable liner. It also has a single black button on the left arm. Is this to secure the armband?? Also, there are stamps on both coat and liner. The coat stamp actually has s stamps (one over the other). Does this stamp indicate the year? Or, something else? I cannot locate a picture of a long/black/leather Nazi coat with a button being utilized to hold an armband but I cannot think of any other reason for it to be there. When I place an armband on the sleeve, it matches exactly where it would need to be. Any thoughts would be appreciated.