Funny... I originally thought it was a '67, not a '57, so extra-super-duper-double-check that era's stampings if the date is important to you.
Here's the backstory for anyone interested, plus more pix.
Example of "Invisible Repair" (Dunhill EC) :: Pipe Repair and Maintenance
Something that gets brought up occasionally around here is that so-called "pipe repair" is a spectrum that runs from only restoring functionality without regard for appearance, to making a pipe look literally new again. Meaning, if the repaired pipe was sent back in time and dropped onto the...
pipesmagazine.com





