Lehman Brothers’ Structured Asset Securities Corp. shelf ranked as the top securitization program for non-agency MBS during the first quarter of 2005, according to a new ranking and analysis by Inside MBS & ABS. Lehman’s SASCO shelf accounted for $21.23 billion in production across the spectrum of non-agency MBS product types, an increase of 35.0 percent over the volume issued through the program in the fourth quarter of last year. The biggest issuance came in…