I know this has been covered (currently *tile hall thread*) but...
Elderly David Brown tractor fitted with Q cab and hence sound reducing lining.
The lining is a flexible sandwich of Elephant hide vinyl over about 6mm of foam backed with some sort of fabric inner.
The problem is choosing the most suitable adhesive to re-fix. The area is approaching 1m2 over the curved inner surface of the metal mudguards.
40 years ago, I would simply apply contact Evostick to both surfaces, allow to dry and then attach with a pressure roller. Is this still the best way or..? Low foaming PU spray sounds easy...