A C-prefix Airweight with a five digit number would be a K-frame (from 1949), too early for a model number. For a holster, the only other thing that matters is the barrel length.

PS: The only problem is that after checking the SCSW, C58xxx is too low and too early for an Airweight; standard production began around C223999.

Are you sure you're not mis-counting the digits and missing one?