So after checking my 1979 Mercedes 300SD, there seems to be a small fuel leak coming from the pump. I have checked and it seems to be coming from the delivery valve o-rings.

I get alot of conflicting information regarding where to get new ones, part numbers and how to replace them. I have been told I can't without re-calibrating the pump. Some people have told me it will be fine as long as I re-torque it properly and don't mess up the shims.

The car still runs. I really would like just to replace the o-rings and be on my way but not if it causes bigger problems. Here are some videos of the leak:

https://www.dropbox.com/s/c1hbkbrc4jaikj7/VID_20180129_163153.mp4?dl=0
https://www.dropbox.com/s/jbf3qwkc8rst3ne/VID_20180128_170130.mp4?dl=0

Thanks
Alan