One cannot have enough baggage in one’s life.
Especially if one is a traveller. On that note, I put together this 18th century style portmanteau to attach to the bottom of my rucksack. It is on the small side for this style bag but the dimensions are based on a convenient size to attach to the backpack and the scrap shoulder I was using. I also foresee this working as a front bag for the scooter or even on the bike.
Outside dimensions are 16″ (40.6 cm) x 7 3/4″ (19.7 cm) diameter for about 680 cubic inches (11 litres). One step closer to a handcrafted life.
Preindustrial Craftsmanship 
Good Job! Let’s see a pic with it on your pack