While original copies are sold through hobbyist sites like Super-Hobby or eBay , digital versions in .rar format are often shared as "scans" in paper modeling communities.

For the best quality and to support the designers, it is recommended to purchase the physical kit from Super-Hobby.

Designed by Marcin Dworzecki, Michał Markiewicz, and Marcin Grygier. Finding the Digital Version (.rar)

If your intent was to find a flight simulator add-on rather than a paper model, there were several high-profile Spitfire Mk IXc releases around that timeframe or for modern sims: Spitfire L.F Mk IXc for Microsoft Flight Simulator

This is a highly detailed published by Haliński in 2007. Publication: Kartonowy Arsenał No. 3/2007.

The physical product typically includes 6 pages of parts to cut out and 5 pages of assembly drawings.

The search for a file specifically named indicates you are likely looking for the Haliński - Kartonowy Arsenał (KA) 3/2007 paper model of the British fighter Supermarine Spitfire IXc. What is "HKA 2007 Spitfire IXc"?

You may find enthusiasts sharing builds or file info on specialized forums like Britmodeller or IPMS/USA . Flight Simulator Alternatives