Hi Kevinbergin,Thanks for showing the trench art,there were some very artistic and clever people with a lot of imagination in the trenches,for instance the intricate rose engraved onto the shell case,it is good that your grandad survived and was able to bring back these mementoes of his time in WW1,I am sure there are some knowlegable members on here who would be able to define the nationality of the shell driving bands by the wavy lines and the width of the grooves in the handle of the letter opener,
Many thanks,
Regards,
Don,