It looks like they've redone the contents. Now its all ZIP files.
Taking a peek inside a couple zips it looks like a variety. For example 1966 has both Dodge factory diagrams and others copied from Mitchel's or Chilton's or similar with no identification or credit cited.
By comparing with the diagrams in the service manuals here
Service Manuals – MyMopar it will be apparent which ones are factory.
Chrysler's 1968 MTSC Electrical Wiring filmstrip and booklet explains how to read and use them.
Chrysler Master Technicians Conference – 1968 – MyMopar
In 1974 there was a follow up which can be helpful with the change in diagram format
Chrysler
MTSC – 1974 – MyMopar
