it is well possible that a FMCB install that was installed with one console works on other console versions as well. I can confirm that my install I made with a V4 also works on my V14 and my buddies V12 (fully unmodded, not using the crosslinking trick, 75kb DVDELF.bin and default loader). I have yet to find out what is causing this behaviour. Seems my V4 has magical powers.
PAL V14 SCPH 75004PSTwo, fully working, XenoPS
PAL "magical" V4 SCPH 35004 PS2, 160GB, dead DVD laser, exploited
8MB official sony MC (Slot 1)
64MB chinese clone MC, Free MC Boot 1.8, Independence Exploit (backup mod) (Slot 2)