Here are those stowage capacities from 2e that I mentioned. For coins just multiple the weight capacity times 50. The baskets, chest, sack, and saddlebags in 3e correspond roughly to the large varieties below while the 3e belt pouch corresponds to the small belt pouch below (based on weight when empty,
Item, Weight Cap.(in lbs.), Volume, Weight Empty (in lbs.)
Backpack, 50, 3'x2'x1', 2
Basket, large, 20, 2'x2'x2', 1
Basket, small, 10, 1'x1'x1', 1/10
Belt pouch, large, 8, 6"x8"x2", 1
Belt pouch, small, 5, 4"x6"x2", 1/2
Chest, large, 100, 3'x2'x2', 25
Chest, small, 40, 2'x1'x1', 10
Sack, large, 30, 2'x2'x1', 1/2
Sack, small, 15, 1'x1'x8", 1/10
Saddle bags, large, 30, 18"x1'x6", 8
Saddle bags, small, 20, 1'x1'x6", 5