In that case an over stamp may have been used. Have not seen one but I have learned to never say never. Chokes 0 and 4 for example were very common in the Flues days. I have seen 1 and 2 on NIDs as well as 1 and 4. Of course 2/4 are very common. Only have seen the 3 once. They used the same choke numbers into the M-37 days. I have a chart that I should probably post that has all the dimensions for all gauges for chokes. It is in my M-37 book.

Last edited by Walter C. Snyder; 07/22/13 08:54 PM.
Walter c. Snyder