Unfortunately no luck with this combination.
I've been struggling to make a fresh Debian 12.4 (upgraded to kernel 6.6) working with my old nvidia 8600gt for a day. But no luck.
After a successful compilation I ran into ignoreABI flag problem. I put this flag into the ServerFlags section of my Xorg.conf but Xorg still doesn't start. IgnoreABI option is taken in account and ignores ABI but server shows just black screen.