Help identifying W.N.Y. 3Pdr 1902 markings

[Obal7]

I would like some help identifying the “Initials” on this Washington Navy Yard 3Pdr artillery shell casing. I would like the help with “E.C.P. (Anchor) J.W.G.”
And if at all possible, the type of artillery piece it was probably from and when it was probably used? Thank you.

[vegetius]

W.N.Y. = Washington Navy Yard

I believe that ECP and JWG may well be QA marks, 3 Pdr and Naval anchor is calibre and service, and 12-1902 the month and year pf manufacture.

[Obal7]

What are QA marks?
Thanks for the info.

[vegetius]

Quality Assurance. The inspectors marks and possibly the assemblers marks for who put the components together.

[Obal7]

Gotcha. Thanks!