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In my experience the Maeda frame ends were employed on the model 318 at this time. The models 319 & 320 received the Campag 1010 ends set.
One U.S. stockist for Crescent bicycles in the 1970's was the REI (Recreational Equipment Inc.) chain.
The forum has had quite a few discussion threads on Monark/Crescent bicycles in case you would like to explore them.
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