Hello,
Now, the six cylinder W108 (280 series with M130 engines carbureted or injected) sedans have exactly the same oil cooler. Same part number and I believe the W113 cars have a 108 part number. Only the v-8s have the aluminum cooler on the oposite side.
Yes, many of the W114 cars had a very similar steel cooler, different mounting and no drain plug on these versions.