Interesting history story, but a few minor points need clearing up. I have been to NAS Lemoore, working there in the 1960s and to San Francisco and they are about 175 miles apart with NAS Lemoore sited well inland in the central San Joaquin Valley.
But, more importantly-all aircraft registered in the United States of America bear the prefix N, standing for November in the ICAO aircraft country code prefix allocation. If someone wanted it to stand for Navy, that is purely coincidental, unofficial and not an acceptable identification to an FAA Air Traffic Controller who would have been looking for a US Naval warbird aircraft November693Mike, not Marine.
Nice to hear from an "over and back" who has spent a few months working in the States. Lemoore is usually referred to as being outside San Francisco, just as Edwards AFB (that stands for Air Force Base) is referred to as being outside LA (that's Los Angeles for those who have not been there.)
Everyone knows what the N stands for, with regard to American registration. What Garrison did was quite simple - and not requiring a great analysis. He simply took advantage of the mandated N in the N Number (That stands for American Registration) and added the 693 and an M. In the publicity for this aircraft he mentioned the assistance rendered by both the Navy and the Marines.... thus the N693M - coincidental or not. He would usually call up...693 Mike on approach, or whatever.
Most controllers, on the West Coast (That's the 10 western States) were familiar with 693M and its pilot.
Why is it that these sites are haunted by knit pickers and specialists in wing loadings, pounds per square inch and minute statistics, overlooking the bigger picture.
Google Lynn Garrison Aviation and you will see something other than statistical distances between Lemoore. For the sake of accuracy, San Francisco and Lemoore NAS are 210 miles apart, not that it really matters. For someone in London, or Paris, the base is still "near, or outside San Francisco."