We're talking about leatherette (vinyl) not actual leather, right?
From the polyvinyl chloride manufacturers association: "Although PVC swells or dissolves in aromatic hydrocarbons, ketones, and cyclic ethers, PVC is hard to dissolve in other organic solvents."
Do not use brake cleaner (non-chlorinated), it is mostly acetone, which is a ketone; do not use toluene or xylene,those are aromatic (cyclic) hydrocarbons or mixtures containing them (gasoline). Use a non-polar solvent such as "odorless mineral spirits" or kerosene, that shouldn't have aromatic content and test it on an inconspicuous area first.