Ithaca had to have loved the guy! I have a 1930 7E Knick that was handled thru Boa. The Depression happened fast and by 1930 most everyone was on vacuum.
The 1931 Sportsman Review list DeWitt's average for single targets as 0.859 and 0.8633 for doubles. I can not turn him up in Ancestory.com. He would have been using a SxS for doubles. The Daly he turned in or maybe his new Ithaca7E?