I have no clue if this is an actual Belstaff bag but it was expensive and even if it isn't the classic one—or even a Belstaff—it's aesthetically pretty perfect. I can always
Belstaff | Bags | Belstaff Travel Bag | Poshmark
Leather bag Belstaff Brown in Leather - 26930114
Belstaff Military Roadmaster 1943 – Backpack - Catawiki