I restored an antique gas station island light with a porcelain shade. I discovered on mine, like many older items, the socket could be completely disassembled and cleaned and put back together with new wire leads. Worked as good as a brand new socket and saved the long hunt trying to find a match. Used the original copper contacts and threaded sleeve after cleaning.
If your socket is for the larger size base light bulb (don't know what they are called), but is usable or restorable, you can get a screw in adapter that will bring it down to the normal household base size. I am using some of these.