DIY Carbon Monopod?

[fnf01]

I'm trying to figure out how I can get what is essentially a carbon fiber monopod, in a perfect world it would just be a 4th leg of a Fatboy Elevate 2. (I've asked if they would sell just the leg but no word yet, I'm guessing its unlikely) I'm fairly certain I could find the appropriate carbon tubes for the legs but what I can't find are the twist locks. Anyone know where I could buy similar twist locks for tripods I can't seem to find any anywhere no mater the size. It doesn't have to be exatcly diameter of the fatboys but again in a perfect world

 

[rogerdoger]

Are you using just to glass off of? If so the easy buttons would be the Wiser Precsion 3rd leg, think its like $60. If you are only using it for binoculars the Wiser Sparrow works awesome with just a hiking pole.