The 1967 Auto World catalog mentions the MPC Miller "91", as well as the MPC "Stilleto", a show car commissioned by Bob Larivee and built by Ron Gerstner. The same catalog also mentions an AMT Porsche 911 in 1/25 scale.
Mark...interesting info in your response about that AMT Porsche 911. When I was doing commissioned work for AMT in the mid 1970's, I saw the 1/10th scale wooden buck for the 911 sitting on top of a desk in either the Engineering or Art Dept. I vaguely remember an explanation of a cancelled project. Porsches at the time were of little interest to me so I didn't ask any further questions.
In later years, I just presumed it was planned as a continuation of the Trophy Series lineup (300 SL, Avanti, Cobra et al), which would have put the intro sometime in 1966. but your quote above is the first definitive proof I've read that links it to that specific time period. I think my earliest AW catalog is 67 1/2 or '68, so I just probably missed the 'announcement' by a few months.