Sarco is helpful for some things but not this. I went through the tent pole thing a few years ago when I was getting them for my Army WWI and WWII shelter halves. I know what they are showing at SARCO in their photo is incorrect for the time period. They will all work of course, standard sizes but the poles in WWII weren't painted green and the rope was white cotton.

I have a USMC book which shows everything but the poles and period photos on the islands shows them setting them up in every way possible except the correct way and usually using sticks for poles.

I know the Marines usually had their own contracts for things and typically changed the specs for them as well. Something as simple as a tent pole you would think would not require overthinking, but I did find a weird one on eBay which is stated to be a USMC set and at almost $200, I'm not willing to shell that much out even if it is correct. The shelter half is pricy enough without adding that much more to it although I did get a pretty good deal on it at about half what most are going for.