Yes, Henk is referring to the (Dutch-)Aceh war. That's when most of the rencong got - ummh - collected.
Looks like the inlay is gold or souasa. This is not cheap tourist stuff.
Yes, seems like some valuable materials were used for this piece. Would be interesting to test both the inlay as well as the ferrule for gold and silver content; also the hilt material could be narrowed down, I guess: how does the tip of the hilt look, any Schrade lines, really no tiny dots from blood vessels?
However, the piece does look off to me: inlay sloppily done, hilt carved from insufficient material (flattened areas rather than evenly curved), blade shape weird (even for a Gayo blade). Technically, one might even argue that this piece isn't a rencong: no decent duru seuke (blade flaring out at the base) nor taku rungiet (the little "ears" at the front of the iron ferrule) nor any of the other characteristic ferrule features (octagonal cross section, file work).
Obviously, this is supposed to be a rencong though and it was done with far more skill than the tourist crap commonly seen on ebay but IMHO it's equally far from 19th c. craftmanship. My best bet is that this might be a ceremonial dagger for weddings - possibly 2nd half of 20th c.?