Hi h
In this case I would suggest, fault finding...
Start with the following on your...
-Jack the car, shake the wheels in a manner to check if it aint the bearings, sometimes u mite just need to tighten them up...BE CAREFUL , not to over Tighten....
-Prop Shaft could be checked as well, by just going under and see/feel for play from the universal joints, also check by ear....
-G/box Mountings--if shot, it can cause vibrations to your prop shaft in return. And yes,, U joints and prop shaft can cause major vibes, also a clunk noise when u shift gears or take off fast...
-did u check tie rods
-ball Joints
-Steering column
Do u have a 5 or 4 speed g/box?????
Does your tyres still touch on the archs at times...could be a warn tyre???
Generally, vibration caused by warn out/warped disks are mainly noticeable when brakin,,,,
Just my 2 cent worth