Saddle soap on the leather is good, but don't clean the inside...I would leave them open to air out for a week or more then put some open containers of kitty litter in them ( the odor absorbing kind) close them up and leave for another week or more and see if the smell is gone. If not, then try Fabreeze and close them up with one of those bags of moisture absorbing stuff you put into closets. And you might try closing them up with a mesh bag of cedar chips.
Congratulations on your wonderful vintage luggage!
Linda C

I agree with linda. Once you get the smell out stuff them with newspaper and a good dose of your favorite perfume sprayed on a couple pieces of the newspaper. Newspaper is odor absorbing and should prevent the odor from coming back over long term storage and newspaper also absorbs moisture sounds like the the luggage might have sweated in the heat over the years sometimes.

Even a good dose of Febreeze along with the newspaper for storage will work too might even be better.

After the cleaning, I used a product called Leather Balm to condition the suitcase. I also use this product on my leather jacket and boots etc. I got the info and the product from a shoe repair shop. For the inside, I would use a car freshner I purchased at Wallmart, the crystal type.

A bar of soap inside a sock, placed in the suitcase should help with the smell. I actually store my suitcases this way & it works.

sunshine outdoors - baking soda, white vinegar can be tremendous help

I have the same problem as Sarahkate. The musty smell is mildew altho it can't be seen, it can be smelled. Probably under the satin liner, on the back side of the leather. I've tried Fabreez, setting them in the sun for days, baking soda--nothing works. I suppose the liner would have to be ripped out, which I hate to do. I wanted these old suitcases to store my scrapbooking supplies.