I find this post quite interesting, even though it does not give more info about 3051:
Advice on selling original '65 SC 427
CSX3058 was sold to the VP of Sony Trading Corp, and shipped to Tokyo, CSX3060 went to Kobe, CSX3062 was also shipped to Japan. As of 4/97. CSX3064-CSX3069 were "under construction", CSX3070-CSX3100 were in "frame only" condition. All of which were produced after 1991. (also from the 1997 SAAC registry)
Perhaps Bill (Mr. Mustang) can tell you more about 3051.
I personally saw CSX3063 as a roller from Cobra Restorers(?) at the '95 Convention. Heavily scrutinized by a man with a ruler in his hand.