Welcome to the forum.
My 260z had only been off the road for 10 years but, as you have found with the visible rubber bits (seals etc.), anything rubber tends to deteriorate with age so I expect all of the underbody rubber parts will need attention (steering rack mounts, sway bar rubber, ball joints, lower control arm bushes, engine mounts, gearbox mount and diff mount. That being said, given yours has done so few kms and has been garaged, the rubber may not be that bad?
One way to find out what is needed is to take it for a roadworthy - you will get a nice itemised list :-)