A "real" Schrade is one that was made by Schrade. i.e. both the brand name and manufacturer are the same. there are USA made "Schrades" that were made post Schrade closure in 2004, by Camillus and Bear. the new owners bought the rights to all the trademarks so you will see, for example, "Schrade Walden/USA" tang stamped knives that were made post closure and are quite exact copies of the original 1947-72 Schrade-Waldens. but they are not true Schrades; i.e. not manufactured by Schrade.
it's a minefield of mimicry that took even the established, very knowledgeable, Schrade collectors a couple of years to sort out after these non-Schrade USA knives first appeared in 2005. remember i said they are near "exact copies", even down to clear plastic tube and carboard insert.
the Schrade Collectors forum here at BF is probably the single most authorative resource anywhere and has most friendly, helpful regulars.
if in doubt about a knife, post a link to the ebay listing in Schrade forum and you will get quick and accurate advice.
roland