That is a GeneralMotors/FisherBody Mfg Dupont Mix Code
926 = just means Solid / Non Metallic
97689 is the mixing formula number
1966 Cadillac Mist Blue -Code 20 - WA3505
The civilian/aftermarket Dupont paint mix number is 4720L
That is the number a Dupont paint jobber/supplier would use for the mix and on the label. After looking up Code 20 from a 66 Caddy.
That is the best number to go by usually, if trying to cross reference in future.
Versus the 97689 Mfg #
L = Lacquer
it also equals the lowest price code suffix. (same price as White and Black)
I used to mix Dupont automotive paint at a jobber in the early 80's
LH, LK, LM, LT etc,,, were higher priced colors going higher up the alphabet
926 prefix replaced the old 93 prefix later into the 60's
Ditzler/PPG - 13151
Dupont - 4720L
Acme - 5091
RM/BASF - A1804
Sherwin Willy - 147
No guarantee this would match to the car now.
It should match any jamb areas that are still factory paint.
They probably picked a close match from a paint chip book when they repainted it.
We should have just told you to check behind BOTH door panels.
In the late 80's i found 2 different buildsheets in 2 different Atlanta cars (71 and a 72) and thought it was driver side, from distant memory.
HeavyDuty Congrats on the lucky-duck find !
Cool how they noted to use an Adriatic Blue Endura
Endura cars with Special Paint got generic color Endura (usually black or white), and Dealer had to paint them to match.
Quart of un-thinned lacquer usually accompanied the car from the build plant.
I don't know how each dealer handled the additional labor for that.
Most probably required an additional up-charge.
http://paintref.com/cgi-bin/colorcod...=1966&manuf=GM
https://paintref.com/cgi-bin/chipdis...&info=&page=32
Scroll down to bottom of that page for color chip