Some of the "Fine Damascus" barrels were 2 iron

[Linked Image from photos.smugmug.com]

"Diamond Grade" crolle was usually 3 iron, which is what I believe your pattern is, but the images from the seller are low resolution and blurry.

[Linked Image from photos.smugmug.com]

Other Diamond Grades were Bernard, and this spectacular Corche pattern

[Linked Image from photos.smugmug.com]

Post a close up of about 4" of barrel where the contrast is most apparent after you receive the gun and I'll confirm

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