Buy a Barbour waxed canvas messenger bag if you want a bag that is BIFL and will look timeless. You can also send it out for any repairs if necessary. Best 20€
Barbour Waxed Canvas Tarras Bag | Nordstrom | Bags, Barbour wax, Commuter bag
Barbour Sporting Cartridge Shoulder Crossbody Bag Green Leather and Waxed Canvas | eBay