Searching on the internet I found these two images of the same sword....looks very similar to mine. Unfortunately there were no references or information about it. So ...at least there is more than one.
Below are two pictures from Artzi's site the first are markings on an Afghani Poulwar , the second (which has identical 'circle' markings as my own) is Indian and on the blade of a Tulwar.
As the Piso Podang has Indian influences I've been looking for a possible link with Tulwars and SEA......so far ...nothing
Regards David