I also have this photo of this "KM" peg. Hopefully it is still there (it was in late May 2017). Unfortunately a number of dickheads (locals or pilgrims - if the cap fits) unthinkingly think that this would be something better on their bedroom wall.
This site is run by Ivar at in Santiago de Compostela.
This site participates in the Amazon Affiliate program, designed to provide a means for Ivar to earn fees by linking to Amazon