Can you help me identify this countermark?

[Flapz]

Hello,

I have a coin that I can't identify neither the countermark on it.
Maybe can you help me?

I just know that romans used the greek alphabet for their countermark. ( ACTA ACCLA - Countermarks on Roman Coins: A Brief Introduction ).

Thank you!

 

[Silver Searcher]

They could possibly be bankers marks.

SS

 

[Mackaydon]

What is the backstory?
Where found; or was it purchased?
What story goes with the coin?
Don..