Physical original manuals appear on eBay from time to time. Searching for "Heidelberg KORD 64 original manual" yields spiral-bound or hardbound copies. Purchasing the physical book allows you to scan it yourself into a high-quality PDF. This is the best option for purists.
The KORD (K-Offset-Rotations-Druck) series was designed for speed and reliability. heidelberg kord 64 manual pdf
Why exclude manualslib/manualmachine? These sites index the PDF but only show 3 pages, forcing you to pay $20–30 for the full document. Physical original manuals appear on eBay from time to time