[Mr70]

It's wasn't Lemans blue,it was Mulsanne blue.
Besides Buick,that 927 AF-017 code was known in 1970 by Chevrolet as paint code #26 Mulsanne Blue.
Aka...LUCITE code #5190L or FISHER code #4069.
It was an std. RPO color for the 1970 Corvette,but was known as one of the special ordered paint colors to be on the 1970 Chevelle.
So far I've seen 5 other 1970 chevelles with that code.Both Malibu & SS.
Two 1970 Monte Carlos as well.
Beginning in 1971 to 1972 it was an std. RPO Chevelle color.
In 1973,1974 & 1975,it became known as code #26 Bright Blue Metallic.

Also,get a 1970 assembly manual and compare the drawings in the body section to look for certain firewall piercings that might indicate if it was even a Super Sport.