An afternoon trip to the Joseph Campau Street St. Vincent's thrift shop netted a cool ashtray Tuesday. 'Dude, it totally looks like it would have been on Dean Martin's coffee table,' discoverer Marc Reiss told friend Scott Ratner. 'It's green ceramic and triangular, and it's huge.' The ashtray's most perfect detail, Reiss said, which more than justifies its $2 purchase price, is a raised center featuring a full 12 cigarette notches. 