I've looked in my copy of War Baby! for the reference to the 50,000 IP receivers I thought I saw mentioned there but couldn't find it. I own about every major M1Carbine reference book printed, just my luck I may have seen it in Harrison'sI'll have to look through War Baby Comes Home next to find that 32,000 figure you mentioned, Dave but in any case I believe whatever number of IP receiver carbines were accepted by the US government are included in the total of 223,620 that S'G' was credited with having produced.