Caveat Emptor
If the buyer visually inspected the items formally prior to sale and accepted the transaction, the seller is relieved of his liability in most cases. This is not an engine with internals nor along the lines of a vehicle with numerous parts that can be mislead as functional.
These are rockers, and if the buyer did not recognize these as the wrong application, he should have postphoned the sale until verification of his application.
This thread is about done. Last words?