Stumbled upon an old Carlton at a thrift store. Tempted to buy. Its my size, probably late 60's, chrome head lugs, fastback stays, zeus dropouts and crankset.

The oddity are three cable guides? along the top tube. Look like they are broken or perhaps missing something. Any clues to what these are? In all my years havent seen anything like it. Its three raised oval braze-ons with a a hole in them. Must have had some sort of guide for brake cable. New one on me. Any help appreciated

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