I put an area 419 arca rail on my cz457 vpt in the manners stock. I imagine the 457 at-one would install the same way. Basically all I did was use the insert that the front sling swivel stud is threaded into as the first hole to attach the arca rail, then marked where I wanted to drill the others holes off of that. I'm pretty sure I used the front action screw as a spot to temporarily attach the rear of the rail to get the line straight, but I didn't mount it using that screw, if that makes sense. after I drilled the holes for the other mounting screws, I used a spade bit of the correct size to drill in the barrel channel using the holes I had already drilled to mount the giant sex bolts that the arca rail comes with. All in all it took no time at all. There's a video on how to do it on area419's youtube channel. The hardest part about it was finding the balls to drill holes in a manners stock.