I bought this fork years ago, but i put it in a draw and forgot about it, thought it was nothing. It looked silver plated, now after i cleaned it up i'm not sure. It appears to have carved out decoration, i'm not sure how you would do that in any other way. It also seems to be engraved, and it's the same on both sides. i could be wrong but it seems they went to an awful lot of trouble for a silver plated fork, so i decided to post it here just in case. It's not marked at all. It shows no signs of being silver plate, been right away around it and everything.
Edit: it's really silver coloured, my photo is just bad.