I recently purchased a large package of 914 parts which included these manuals. These are the maroon cover and also have 1975-1976 information but no wire diagrams.
Anyone know if they're were not included with some of the later runs? Thanks in advance, Brad

Wiring diagrams in color should have been included in section 9 in the set. I never have seen a set that included the -6 diagram though.

The 1970 914/4 and 914/6 wiring diagrams were issued in the 1972 supplement to the 1970-71 Service Information booklet. It is downloadable on my 914 Classic website from the Factory Tech Publications webpage

Even the wiring diagrams in the service manuals are prone to rust away.