Mike I'm sure you are right however it looks like a carbine staff will work,they are close to the correct length and have a provision for the spring. main difference as near as I can see is the range markings, the photo in Olsons book is in yards or meters, the military ones I guess are marked in mils. Got one on order, we'll see.

I learn something every day, and a lot of times it's that what I learned the day before was wrong