The top oddity mark is probably a maker's mark or a deceptive design that they used on a special line...in this case a copper base metal...which was beyond their common working lines. However poor, it looks complete and could contain a letter like "H" or a letter pair. But, it looks unequal in this orientation. If rotated on the axis, it might appear like a device forming a cross of Lorraine (aka raincross), with the upper crossbar narrower than the lower. For now, all this gets us nothing until that can be matched to a known name.
The four digit number could be a model, pattern, stock, catolog, or internal control designator. It doesn't matter yet. What is important is that being in the thousands, it may suggest a large or long lived firm, or both. At any rate, they had some output and an identity could surface.
Not to distract from the question, but here member 'blackstone'' has left both English and German names for the "equal cross" device which has been long used by platers:
viewtopic.php?f=24&t=18465&p=58471&hilit=cross+device#p58471Now, the cross is often used as a mere pseudo-mark rather than an actual identity (trademarks, etc.) and usually applied only once, alone or in combination with another device. Here it is used twice, like brackets, which raises the question of whether it is simply fill material for a normal set of letters in equal shaped cartouches where the EPC (for Electro Plated Copper) has substituted for a letter set. There could be numerous British firms that might have worked for a case of four cartouches, and probably a few for five. One of the American makers that comes to mind is E.G. Webster & Sons, using EGW&S all in five equal octagonals (boxes with clipped corners). But that is only suggestive and not conclusive in any sense.
At this point we're stuck. It may be necessary to have photos posted of the entire object for someone to get a feel for where and when it was created.