Here's a nice but slightly rusty example of a W116 280SE with some AMG modifications. The trunk lid gets a flush mounted wing, and the front air dam is replaced with a larger one that reaches much lower and has a lip kind of like a splitter. There's no AMG badge on the trunk, and I don't think AMG did anything with the 280SE. These parts are probably from the AMG 6.9 program. Lorinser also had W116 parts, but also only did work on 6.9s I think. Hopefully we can restore the euro bumpers to their former glory. Also for reference here is the rear lower quarter panel and areas around the rear which are being repaired.
Nice rear wing
With AMG air dam
Factory air dam
I don't think AMG had an engine tuning program for the M110. It doesn't make much sense to add power to that engine without changing the transmission.