From Gun Digest 1972, 25th Edition (pg 282), John T. Amber, Editor (Digest Books, Inc., Northfield, IL, 1971; ISBN 0695-80222-4)
From Pistolsmithing (pg. 412), by George C. Nonte, Jr. (Stackpole Books, Harrisburg, PA, 1974, ISBN 0-8117-1133-1)
Here are some more pictures send to me by an Internet friend.
I have no more information on this conversion, which was brought to my attention, by Walt Kuleck, author of "The AR-15 Complete Owner's Guide" and "The AR-15 Complete Assembly Guide - Build your own AR-15!". Thanks Walt!