smp190,
The "CH" after the serial number cannot indicate a manufacture date of 1927, since it was finished and proofed by Oct. 1913. The crown S means it was proofed for shot; a smoothbore is sometimes found with a crown B which means it was proofed for a single projectile (bullet). At this time the crown W only means the barrel was choked, the amount of constriction was not shown or indicated but they were usually pretty tight, especially considering the use of modern wads and shot cups.
Mike