As far as Seatbelt.kext and System.kext if you pulled them from 10.5.8 on your G4 they should be fine. You can double check though.
mach_kernel 9.8.0
System.kext 9.8.0
Seatbelt.kext from 10.5.8 (Build 78) You can check this by following the directions below. http://www.infinitemac.com/f5/update...lt-kext-t1992/

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