www.925-1000.com

http://iforce.co.nz/i/gvrbhxrk.rjk.jpg
The hallmark after the N, looks like some ostrich
These hallmarks are on a silver tray, if that helps :)

Maker WMF
http://www.925-1000.com/silverplate_W3.html

EPNS for electro plate nickel silver

N = for Nickel Silver

I/O = Normal thickness of gilding or silver-plating

OX = oxidized

http://www.silvercollection.it/WMF.html