Let us know what you find out !!

No idea about the wing. it was like that when I got them. I will take them to a jeweller. My research on him regarding spoons is vague too. Thanks for your advice.

I can find no record of Giacinto Melillo ever making silver spoons !! There are none to be found so no way to determine value without something to compare !! And since they are not marked for purity with either 800 or 925 which is the Italian standard for silver,,cant even guess at melt value !! I would suggest you go to a jeweler and have them tested for content !! As far as him being the maker of the spoons I have no idea !! Many times there are things produced in a studio that the artist himself never touched !! His design but made by others !! That also affects the value !!
How did the wing get broken ?? 2nd pic ?? That is going to affect value !!

No, they are not marked. I have read that he did not always mark his work. I have attached a photo.

No matter about the box,,he is known for his work in silver and gold and that should be marked on each piece !! What does the box say they are made of ?? Still need a pic of one of them !!