Similar to the hilt, the pattern contains hint of Siamese art. To be more specific, Ayuthaya period or earlier. The most familiar pattern at the edge of the guard and the diagonal on the hilt.
I went to Ayuthaya last weekend to check for the zigzag and twisted rope. But they are not used on temples and artifacts which are recovered within Ayuthaya city. My feeling is the art was mixed with another one. From the detailed pattern, IMO: 's the Dahb could be for sword of a province ruler or a noble. The province 's not Ayuthaya itself but a smaller city with bronze-cast hilt tradition. I have to do more research
What is the stuff in the gap between the guard and the blade? Is it earth? Is it possible to get some information from that thing?