Just purchased a pair of these bags from a thrift store,they were marked as Donkey saddle bags.

Going to use them on my bike, The leather straps matches the other leather accents wonderfully but with design of the bag itself looks like it will collect water and debri.
I don;t ride in the rain but still would like to preserve/protect the canvas and threading but how to go about this?Aerasol sprays results used in the past were dismal at best. Any suggestion?