I noticed that anomaly as well Larry, but assuming the serial number dates are accurate,the action and barrels may have been proofed in the white just before the 1925 rules came into use at the proof house.I have a MacNaughton RA with damascus barrels that has one set of original nitro proof marks which date the proofing to 1896-1904 yet the serial number dates the gun to 1922!!
Nothing ever written in stone...


Better to keep your mouth shut and be thought stupid,than open it and confirm.