[LAU] 2.6.25.4 rt-patch / which patches applied in 64studio-Kernel 2.1rc2?

hi, i want to get the same kernel-source as used in 64studio 2.1rc2 (named 2.6.21-1-multimedia-486 #1 SMP PREEMPT RT) does anyone know, which patches are applied to the original-kernel-source "linux-2.6.21.1.tar.gz" which i can download from kernel.org? where can i download the patches? unfortunately i even cannot find the RT-Project-patch for 2.6.21.1 on kernel.org :-( or 2nd chance: how can i use my old config of 2.6.21-1 (/boot/config-2.6.21-1-multimedia-486) for a new build of kernel 2.6.25.4 with patch-2.6.25.4-rt3.gz. which patches do i need therefor? many thanx mike p.s.: thanks for all your help in the past!! i did'n see such a wunderful community like linux-audio-user before! really great!