Thank you!Liqui Moly 10W-40 is a German oil with the correct amount of lubricating additives for the Vintage Mercedes-Benz engines.
You can get it from Amazon.com for a reasonable price.
On a recent (March, 2020) MercedesSource.com YouTube video you can learn more about it.
Thank You!I use Penrite HPR30 (20/60 in my region) which is a mineral oil and has a zinc additive, in my M116. There are different oils produced by different manufacturers that are similar, so check with your local suppliers, or the person that re built your engine.
I wouldn't go for a synthetic or synthetic blend in that engine.