These vintage baby shoes are size zero according to the tags and were made in Japan. I'm not sure of the age but they came in a box of doll shoes from the 1960s and 1970s. They are approximately 3 1/2" long.
These have a few age-related blemishes and I'm not sure they would stand up to being used by a baby, but they would be adorable on a reborn doll! See photos to see blemishes, mostly on the soles.