Lots of things are interchangeable between models built within the same time frame. 108, 109, 110, 111, 112, and 113 have some commonly used parts. Brakes, suspension, transmissions, engine parts, steering wheels, door parts, gages, fuel pumps, and some interior parts. Not all parts fit all of these models but some pieces do. A 300SE shares very little with a 113 but a 111 coupe has much in common with a 112 coupe.
Even a 114 has a few parts in common with a 113 but it shares more things with a 107.