According to Proofhouse.com, it was made in 1919. As far as ammo goes, look around the Internet for .38 S&W. It's not a common caliber anymore, but it is readily available online. Able's (
www.ableammo.com) has Winchester 38 S&W in stock.
.38 Colt is the same round, but with a flat-nosed bullet. I don't know if anyone sells the caliber with that name, but it'll work just fine, too. Same with ".38 S&W Corto", which is what Fiocchi sells.