Chasam60
I do not own that gun but i would have a hard time calling that a Marlin Ruger MLS-50
I certainly looks like a "Black Diamond" to me.
I really have never heard of a "marlin" ml so maybe they did make one other than the Ruger that i am accustomed to - but i really thought I had seen most of them...
Gotta give the owner the benefit of the doubt - it must be a Marlin but is is new to me... can not believe thay made to many of them...