Hello Yves,
Thanks for sharing again!
This blotchy pattern is sometimes seen with barung blades (only AFAIK) - the blade exhibits the typical laminations from preparing the steel: Apparently chunks of steel get combined with milder steel and result in these blotches after forging. See
here for another example!
I haven't seen this pattern with any modern barung blades - I guess this dates back to the 19th c.
I'd place this ensemble before WW2, possibly from around the middle of the first half of the 20th c.
This pommel crest style seems to be a later development of Junggayan hilts but I am not sure if this type has any specific name.
The color looks like rust to me but might as well be from varnish...
Regards,
Kai