This was my great-great aunt’s – so keeping it!  Just trying to identify and get a replacement part – how would this item be described (assume a coffee server)?  It has lock bar (?) – when removed server tilts to pour.  Marking on the bottom reads 4 Pint EPNS for electroplate, but can’t find any other marks.  It is missing the knob at the top, so looking for advice on where I might find a replacement; and, other than elbow grease how best to polish.