Galen Leather A5 notebook cover. Quite possibly THE best leather I've ever seen and for some strange reason to me at least is that they are out of Istanbul, Turkey. Truly amazing. :
Notebook Cover (A5) - Lorton & Horn
Stalogy Cover B6 365 Days Pen Loops Natural Horween Leather Notebook Cover - Etsy UK
Handmade Italian Leather A5 Notebook Cover - Badalassi Carlo No Fin – Ross Hugo Leather