Need help on this barrel band

[Matteo]

Hello Bruce,
I can't take pics right now, but the rear sight I found on the carbine when I got it is a L shaped no marks, no S, soft metal with signs of flat screwdriver used to put it in place.
I already changed it with an original RR. The metal of the RR one is different, a lot harder.
Front sight is slightly marked RIA on the left side. I bought a RP machined front sight that I still have to install.
All my new pieces come from Roger Mickelson, so I'm sure they are original.

But I have another question for you, I'm returned yesterday from a great d-day trip in Normandy in which I visited some militaria seller including the famous AMS near Brussels.
Bhere I bought some piece hard to find here in Italy, and my dad bought this front barrel. Light in AMS was not so bright so trusting my eyes and the vendor he bought a type 2 AI barrel band. Home my dad discovered some signs (cutting or machining?) on the bb, so I ask you, what do you think?






sorry for the little oversized pics

have a great day!

Matteo