• • • —Man About Town:| New York's Horatio Alger Jr.:, Marvin Schenck, the talent scout, likes hamburgers. So the other day, while munching on one in a j Sixth Avenue beanery, he noticed a j I youth who impressed him as the « ! most typical good-looking young j American he had ever seen . . . I The chap’s clothes indicated he J could use a job . . . Schenck introduced himself and took him to j MGM's Broadway offices, where a producer ejaculated: That's thehandsomest guy in New York and Hollywood! . . . After an ordinary camera test, it was rushed to the Coast . . . Magnate Mayer of MGM telephoned and ordered the new find rushed West ... On Friday, then. Jim Wittlig, 6 foot 4 nephew of Uncle Sam (who only the other day was hunting for a job on Sixth Avenue) will be riding in class out to Hollywood with a year’s MGM contract His build-up will be Movieland's No. 1 Hero.