Here is the info on C-GAUN from the Civil Aircraft Register. It shows still in service with Air Canada.
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Mark C-GAUN Serial No 22520
Make BOEING Model 767-233
Base Of Operation QUE., MONTREAL
File Location Quebec
Reg Purpose Commercial Flight Authority Certificate of Airworthiness
Category Aeroplane Weight (Kgs) 140615
Year of Manufacture 1983
Year Imported 1983
Country of Manufacture United States Transponder 110000000100011010111110
Owner Registration:
Issue date 1992-06-16
Owner Registration 1983-04-07
Engine: Turbo Fan
Number of Engines 2
Owner Information:
Name AIR CANADA
Multiple Owners No
Address DORVAL BASE 14, BOX 9000,STN. ST-LAURENT City MONTREAL Province Quebec
Postal Code H4Y 1C2 Region Quebec