Oh yes these are used devices but they have been removed from service very carefully (especially with respect to ESD)
National Semiconductor
CMOS
Type: NM27C256Q 120
256K (32K x 8)
120nS speed
These are used, previously programmed. Although they were partially UV erased, it would be wise to erase them thoroughly and start your loading your new program into the device then placing a UV light proof label over the quartz window.
If you should need datasheets, these are available (by request)
Cleaned the window, removed from sockets and handled under tight ESD safety conditions - now stored on ESD foam.