Originally Posted by
juvela
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Thank you for these additional pictures.
The "57" is likely a reference to the frame size in cms - measuring center to top in this case.
In addition to the serial number there appears to be a third number of "86."
[MENTION=20650]T-Mar[/MENTION] may well recognise this serial number format. Wonder if it could indicate a frame made in February of 1976?
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Color is not native. When cleaning the frame, the old paint was bright green.
What more photos? I can measure all the pipes