Bill,

In answer to your first question, the answer is Yes.  Winchester did not stamp the chamber length on the barrels until 1927 when they made the change from a 2-½” chamber length to the longer 2-¾” length.  When Winchester first made the change (in late 1926), the chamber length was stamped on the bottom of the receiver frame under the serial number and just above the loading port.  It was shortly thereafter move to the barrel.  In answer to your second question, No, it would not make any difference.

Bert