'08 gearbox oil leak- rear seal or prop manufacturing fault?

Evening all,

Girlfriends '08 Jimny is leaking gearbox oil all over itself. Oil is everywhere on the underside and dripping onto the exhaust and floor. With the amount of oil coming out I'm guessing the gearbox rear seal is past its best. Buuuuut doing a little research I've found that there's some talk of a manufacturing fault on the prop where oil can pass down the internal splines of the propshaft to the front UJ where it leaks out. Went to the Suzuki dealers today to see if they could look up any past service bulletins for this fault and there was none logged on their system (had a look for myself on their system and everything!) With the sheer quantity of oil knocking about in far reaching places I would say its the latter thats collecting oil on the UJ and flinging it as far as it can. Suzuki quoted me £300 for a new prop assembly which made me wince a bit. Any way to investigate if this is the fault while the prop is out doing the rear seal? and home fixes or look out for a second hand prop and replace?

Also has a wicked vibration under load at lower RPMs. Are dead UJ(s) the normal go to? over there tomorrow evening so can check them then

Thanks! You're all awesome