IRON HEART (IRON HEART／藤田一己) is a manga written and illustrated by Kazumi Fujita, and published in B-CLUB in May 1986
U.C. 0087, during the Gryps War, a Titans pilot flies a Gundam Mark-III, escorted by a pair of Barzams. In battle, he encounters a Dijeh (quite possibly the Dijeh SE-R). Realizing it is piloted by Amuro Ray, he decides to defect to the AEUG -- this is how the RX-166 became the MSF-007.