Yes, M-B printed a chassis manual for W114/W115. Earlier printings were in one bound volume, and later printings were split between two volumes. Another useful reference is the Spare Parts List. Probably the best place to look for these is on the 'Bay.

Some folks sell a CD-ROM with scans from the books, but I found that they do not have everything in them, and that searching for specific information is not easy. I bought two of those CDs from different sellers and found them to be lacking. Nothing I've seen is better than the actual printed volumes.