OK! Lets do a little math exercise. I don't know of any breakdown of Flues Model Ithacas, but there was a breakdown the company published back about 1960 for the NID models. There were roughly 46000 NIDs produced and Ithaca said there were 155 total in Grade 5E. They also broke out the smallbores and the Magnum-Framed guns -- 10 Magnum-Tens, 9 Magnum-12s, 3 28-gauges and 6 .410-bore Grade 5Es -- leaving 127 Grade 5Es for 10-, 12-, 16-, and 20-gauges. I've seen the figures that production was 50% 12-gauge, 30% 16-gauge and 20% 20-gauge in the pre-WW-II years. And, lets say 2% for the 10-gauges and take a percent each away from the 16- and 20-gauges. So, that would give us 64 5E 12-gauges, 3 5E 10-gauges, 37 16-gauges and 23 20-gauge 5E NIDs. There were about 223000 Flues Model Ithacas produced, so 23/46000 is to X/223000 and solve for X. X = 111 Grade 5E Flues Model 20-gauges.
