What material is a hollow handle knife made of?

I have a couple hollow handle butter spreaders with what looks like a chip in the silver. Is this possible? Can anyone tell me what material is under the sterling silver? Is it possible to have this corrected?

Also, how is a blade attached to a handle? I have one piece that looks like some type of glue overflowed where the two pieces are connected. Can the pieces be disassembles and then reattached?

Please see pictures.

picasaweb.google.com/lisamla/Ste … 3opQRXyq5Y

Thanks for your help!