sproul...
As for the issue of modifying your V-peep, I don't believe it will work out like you want it to. The V-peep is made of machined aluminum and there's not much material there to get some threads into on that blade. Further, I don't think the aperture, depending on what you choose, would be able to slide up and down the elevation ramp without interference. You would be better off to go with a Lyman tang peep or try to find one of the original T/C hunter style tang peeps but be prepared to pay dearly for it if you do.
Just my $.02...
BPS