I have a Parker and the factory letter says it was shipped in May 20 1905. The gun has the T-type pinned wear plate that was patented 8/15/1905. The water table is not stamped with the 1905 patent date. Was the gun shipped with the 1905 wear plate or was it added at a later date?? Opinions please.
Picture below

The barrels flats have a stamp WK in a circle is this the Walter King stamp that is thought to be a barrel quality stamp?? Picture below
Also, according the TPS page519 Vol II the end of a 12 ga. chamber is .798 (C Dia. small end) Does that mean that the proper chamber length gauge for a Parker should be .798 dia.???
Thanks Craig (just trying to educate myself)