Yes, once you have polished the area where the pin resides, a touch of cold blue will make it show up very well. Once your barrel is off, find a scrap pipe section that is nearly the same diameter as the sight collar and turn it to the same inside diameter of the inner collar radius to drive it on.
As the collar is being driven on-you can then slightly "steer" with a twisting motion in your hand the collar to match the index marks on the receiver once it's nearly home. With the barrel installed by driving the collar right up to the face of the receiver a nice transition can be had without an unsightly line or seamless transition between the two parts.