Forty years after it was made, The Velvet Underground's first recording has become a financial hit - in cyberspace. Bought for 75 cents four years ago at a Manhattan flea market, the rare recording of music that ended up on the influential New York band's first album, "The Velvet Underground & Nico," sold on eBay for a closing bid of $155,401. The buyer is a mystery, only identified by the eBay screen name: "mechadaddy." But a greater mystery endures: How did the 12-inch, acetate LP end up buried in a box of records at a flea market? Warren Hill, a...