I am looking at a Lockheed - California Company's ID plate formerly affixed to an ex-Eastern Airlines L-1011 Tristar - quote:
MANUFACTURER'S MODEL L-1011-385-1
CUSTOMER'S MODEL 193A
MANUFACTURER'S SERIASL NO. 193A-1040
CUSTOMER'S SERIAL NO. 319
TYPE CERT. A23WE
CONTRACT NO. PROD. CERT. 600
ENGINE TYPE RB211-22CA-02
ACCEPTED 9-6-73
Note that the first L-1011, the prototype was MSN 193-1001so this particular aircraft was the 40th built. I am surprised at the engine model. The first deliveries were all fitted with RB211-22C engines. I thought they had switched to the 22B by the time this aircraft was built but it is 45 years after all. There is no overall serial number indicating what production position this aircraft placed in all of the tens of thousands of all the models of aircraft Lockheed built.
The Customer's Serial Number, 319, is what Eastern painted up front and was what the aircraft was identified as by maiontenance and others..