Where is this sample from?

[kbaccki]

Secondly, I have stated MULTIPLE times that I AM NOT trying to recreate the sample or use any other stuff available on the original library/hardware/whatever, so your tips on that is useless to me (not to sound rude). The sole purpose of finding it is for documentation purposes. Please get that through your head(s).

My mistake. I guess you have a reason for doing this ("for posterity sake") that goes beyond my understanding and intuition. Most people that try to nail down exact sample sources are for song snippets -- a drum groove, horn break, guitar riff, whatever. Most other inquiries are of the form "what type of drum makes this big boomy sound", to which the answer is, inevitably, "that's a taiko"... but it doesn't really matter where the taiko came from, cuz you heard one taiko you've heard them all.

Considering piano scrapes and rakes is such a generic effect, you may inevitably be stuck with "piano scrape of unknown origin", then again maybe somebody will recognize this particular needle in a haystack.

[loachm]

...it is most likely a sample from an older film and your best start would be to look for film scores that have been sampled a lot (could also be a film that's little known, but that would make it much harder to determine a start point). Anyway, one score that comes to mind that uses such sound effects would be Lalo Schifrin's score for Dirty Harry. Good Luck!