It’s a Frith! The Frances Frith Collection. Beautiful Art Nouveau lettering on the blank side, and the Frith code number on the front right hand corner. We might be able to track how old this is, but the styles gives us possibly the 1910s-30s.
Gotthardstrasse (road to the Gotthard Pass), Andermatt. Another long stretch of miles from Trimdon Street, Andermatt is a picturesque ski resort in the Swiss Alps. Someone who knew Martin, a member of his family, a work colleague, maybe Martin himself, went to Switzerland. Maybe even skied. Now – that would be a thing.