Hi James,

Yes, the score is available for purchase at Sheetmusicplus: https://www.sheetmusicplus.com/title/in-nomine-for-organ-digital-sheet-music/21377757.

Because the score is short, the preview at SMP excludes the first page, but you can find an image first page of the score on my Twitter page: https://twitter.com/michaelcalabris.

Thanks for the tip about the creativecoin tag!