Webster Marking

[treasures]

I have a piece with the following marks.

E G W & S

E P N S

77/OX88

I know what the EGW&S and EPNS are but am having difficulty with the 77/OX88. Can anyone tell me what it means? Thanks in advance

[Kit]

Frankly, I don't know -- but I'm willing to guess that it has something to do with pattern / inventory numbering associated with the 1961 trademark change from E. G. Webster & Son to Webster-Wilcox. Again, this is only a guess.

Anyone else?