At 11:47 PM, Marco found it. A single, dusty entry on the Wayback Machine:
In this long article, we will break down exactly what Error 605 means, why older versions of GarageBand (specifically version 6.0.5 or the "top" stable build) are so sought after, and a step-by-step method to successfully complete your download. garageband 605 download top
The official Apple servers no longer hosted the installer for 6.0.5. The internet, however, was a sprawling digital graveyard. Marco began his search that Thursday night, typing the sacred phrase into every search engine he knew: At 11:47 PM, Marco found it