The rifle in this auction has seen its fair share of HK scope mount use.Here's a picture of a 76 import. Notice the ridge for the scope bumper is milled off....
HK HECKLER & KOCH HK91 308 SACO IMPORT PREBAN RARE : Semi Auto Rifles at GunBroker.com
My mistake; the picture I linked above is from a G3. Mine look like this:The bumper from my understanding rides up against the steel ridge in front of the drum. The early ones don't have this ridge- it's milled flat. I have one Saco import and an 80's import with the ridge. Just noticed the difference tonight and figured the bumper would lay up against the drum itself on the early model. Wanted to see if anyone was running one.