Although slightly off topic to the thread but whilst on the subject of polished bare metal finish.
As already mentioned by WHBM, several North American airlines had "polished bare metal finished" aircraft during the 1970/80/90's.
Other than American Airlines which had their aircraft delivered in this way from 1933 with the advent of the DC 3 there were several others including.
Air Canada
Eastern
Flying Tigers
Northwest Orient
Piedmont
Southwest
US Air
Western
Also CP Air with their part bare metal finished aircraft. (Which looked stunning)
Several European airlines also trialled polished bare metal finished aircraft during the same period including.
Aeroflot
Aeromexico
British Airways
Condor
JAT Yugoslav
Lufthansa
SAS Scandinavian
Although in many cases this was short lived and the aircraft were eventually fully painted.
In the case of British Airways I believe that they only had one Boeing 737-200ADV styled in this way.
British Airways Boeing 737-200 ADV G-BKYA in the short lived "trial" bare polished metal finished livery although the underbelly still retained the dark midnight blue.
One of the best looking aircraft was the Condor DC10-30 which was delivered factory fresh in the bare metal finish.
