Michael Gain, sounds like you've done a lot of work and parts replacing with frustration being end results sorry to hear.
Right away mentioning rubber dirveshaft joint brings up a red flag, they are a POS in my opinion vs a true steel cross U-joint. Had issues three times on the 95 D1, first by just removing rear driveshaft for diff seal replacement reinstalling in exact bolt location to center punch markings. Second rubber joint ending up twisting apart, 3rd also twisting apart with vibration issues replacing with a driveshaft with steel U joints. Vibration problem solved 93K miles and counting. Spirited mountain driving with 5 speed and warmed over 4.6 engine hence rubber joint failures.
With front vibrations issues like out of balance wheels like your describing I spent an extensive amount of time and labor also until finding the problems.
Made a stand (3" x 3" box tube) with spare front axle stub shaft allowing mounting hubs front and rear. Seals removed, bearings cleaned and oiled only noticed hubs slightly out of balance with one rather way off balance. Balanced four hubs then installed still good used rotors then checking for runout plus disc thickness all around which wasn't an issue being solid rotors.
Had a vented rotor vehicle that the wife was sent off a highway exit (Calif H. P.) into 15" deep water chilling hot rotors ending up with a couple rotors swelling up with fat sections causing shuttering braking and vibration issues until the pads and caliphers moved back from the rotors. This required a light machine cut all rotors solving this problem.
Back to rotors now assembled onto now balanced hubs tha were also out of bance hence next balancing rotors with hubs. Problems solved considering hubs and rotors show drilled and ground down locations from factory or from the hub and rotor supplier for Land Rover.
Red flag thinking as factory new 4.6 LR short block the cranks were not balanced ending up with a slight crank vibration issue which a low rpm shifting automatic would hide vs 5 speed turning higher rpm's. End of 12 month 12K mile warranty yanked out (2,300 mile) 4.6 and had crank balanced to the piston and rod assemblies I already DIY balanced. Turbine smooth engine 20+ years.
You mentioned banging rotors off with debris broken loose falling out.
Dirt, mud or rocks picked up off roading also can cause out of balance vibration issues.
Under hard acceleration an out of balance driveshaft will calm down with vibration issues but more pronounced unloaded like when coasting in neutral.
As mentioned above, indicate (dial) rotors to see if they spin true after reseated or bolted up to the hubs again plus thickness all around check.
Mentioned 27 mph and again around 60 mph, thinking primary and secondary driveshaft out of balance vibration zones. Sorry long novel.......~~=o&o>.......
Right away mentioning rubber dirveshaft joint brings up a red flag, they are a POS in my opinion vs a true steel cross U-joint. Had issues three times on the 95 D1, first by just removing rear driveshaft for diff seal replacement reinstalling in exact bolt location to center punch markings. Second rubber joint ending up twisting apart, 3rd also twisting apart with vibration issues replacing with a driveshaft with steel U joints. Vibration problem solved 93K miles and counting. Spirited mountain driving with 5 speed and warmed over 4.6 engine hence rubber joint failures.
With front vibrations issues like out of balance wheels like your describing I spent an extensive amount of time and labor also until finding the problems.
Made a stand (3" x 3" box tube) with spare front axle stub shaft allowing mounting hubs front and rear. Seals removed, bearings cleaned and oiled only noticed hubs slightly out of balance with one rather way off balance. Balanced four hubs then installed still good used rotors then checking for runout plus disc thickness all around which wasn't an issue being solid rotors.
Had a vented rotor vehicle that the wife was sent off a highway exit (Calif H. P.) into 15" deep water chilling hot rotors ending up with a couple rotors swelling up with fat sections causing shuttering braking and vibration issues until the pads and caliphers moved back from the rotors. This required a light machine cut all rotors solving this problem.
Back to rotors now assembled onto now balanced hubs tha were also out of bance hence next balancing rotors with hubs. Problems solved considering hubs and rotors show drilled and ground down locations from factory or from the hub and rotor supplier for Land Rover.
Red flag thinking as factory new 4.6 LR short block the cranks were not balanced ending up with a slight crank vibration issue which a low rpm shifting automatic would hide vs 5 speed turning higher rpm's. End of 12 month 12K mile warranty yanked out (2,300 mile) 4.6 and had crank balanced to the piston and rod assemblies I already DIY balanced. Turbine smooth engine 20+ years.
You mentioned banging rotors off with debris broken loose falling out.
Dirt, mud or rocks picked up off roading also can cause out of balance vibration issues.
Under hard acceleration an out of balance driveshaft will calm down with vibration issues but more pronounced unloaded like when coasting in neutral.
As mentioned above, indicate (dial) rotors to see if they spin true after reseated or bolted up to the hubs again plus thickness all around check.
Mentioned 27 mph and again around 60 mph, thinking primary and secondary driveshaft out of balance vibration zones. Sorry long novel.......~~=o&o>.......