Now that the source of this Barong is wide open, I feel I can add my comments:
This is a very nice and complete Barong. We had it since long time and surprisingly none of our many good customer did find it earlier. I can not remember if I polished / etched it or not. Probably not.
To the main question: To polish and etch it or leave the original patina, my opinion is very clear: We should refer to it as the original owner did. If there is a pattern expected to be found than polish and etch it to bring it out. Like other marks of quality (The eyelashes marks, the running wolf, the Assad Allah signature and others) that were copied by blade makers all over the world and at all times, the pattern, either wootz, or pattern welded or laminated is also a mark of quality and the owners were proud to show it to all. During the life time of the blade the owners had to sharpen it and by doing so he erased the pattern and had to polish the blade to bring it back. So why can’t we do the same??
In addition many times polishing and etching brings pleasant surprises. The Barong below was collected in the flea market in New York for next to nothing:
it looks very simple and nothing of particular interest. A light polish and etch brought up this:
It is one of the best laminated Barong blades I have seen.
There was a comment above about the Arabs polishing their blades to mirror polish. To the best of my knowledge it is very wrong. Arabs admire the wootz blades (Johar as they call it) and do every thing to bring it up and show it to all for exactly the same reason:
Look what a good blade I have.
A word of caution: Improper polishing and etching may be a very destructive process.
If you are not experienced, do not try it without good clear instructions