I completely finish the rifle prior to the trip to the range. I consider the testing to be the icing on the build cake. If I need to file the front sight down, I use a piece of plastic from the lid of a coffee can with a rectangular cut out in it to slip over the blade of the sight, eliminating the danger of hitting the barrel with the file. I also like to do this job with my brother...he has two functions - one, he is the vise that holds the rifle while I file, and two, he is a much better bench shooter than I and rings the best out of a rifle's accuracy.
I cut the 'wings' off so that they just protrude a little past the diagonal flat. I never file them flush with the diagonal flat - that looks silly to my eye.
I prefer to drift the rear sight to make up for windage issues...it's easier to disguise than the front sight. I finish once sighted in with a witness mark on both the front and rear. I use a little cold chisel with a cutting edge a little less than 1/8", so there's about 1/16" line on both the sight and the barrel. Almost all of the rifles in Wolfe's Jaeger book have witness marks...makes perfect sense to me.