â Aames Investment Corp. has become the latest subprime mortgage shop to reshuffle its management team and restructure its operations. The restructuring, announced last week, involved changes in key management positions. President and COO John Vella, who joined Aames last year after a long tenure at Option One Mortgage, resigned to “pursue other opportunities.” His job will be filled by Michael Matthews, the company’s executive vice president of national retail sales and marketing, who…