Great picture, I can see the crossing lines are very different from what I thought. I'd also suspect the lines were there before the engraving was done. Just my opinion, but your link of the Holland & Holland seems to be a different effect from your new picture.

I think the link is an excellent example of what others are describing. Possibly, wrought iron slag inclusions appearing as lengthwise irregular grain with signs showing through the whole piece.

I think it's possible to put a fine finish on wrought iron. If those slag lines are there, I wonder if they might be revealed by a mild acid etch such as years sweat from normal handling. I wonder if that H & H had most of its lines show about where it balances or where it cradles when it's broken open. Just wondering, thanks for the topic.