I have the same Made In Taiwan and 502 decals on my 1983 Raleigh Marathon. Look at the insides of the cranks to see when they were made (mine say 83 D for April of 1983... I think). Your bike is from the era when most of the Raleighs sold in the U.S. were built in Taiwan and Japan under contract to Huffy who had licensed the Raleigh name in the U.S.
My Marathon has the same derailleurs and they work flawlessly.
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I stop for people / whose right of way I honor / but not for no one.
Originally Posted by
bragi 
"However, it's never a good idea to overgeneralize."