This isn't Gardone Valley or Leige. This is free advice on the internet, some good, some bad. I've looked at dozens of hooks on factory guns and all cut to size with milling machine indexed to location, and end mill ground to diameter matching the pin. Perfect radius. Then final fitted with spotting technique. A CRAFTSMAN with file can do it on rough welded hook but they are men that apprenticed and did many hooks with some rejects along the way. Here we have someone doing it right first time and getting fit correct in the X, Y and Z axis. You can get a gun rejointed by one of several craftsmen for $2-300. And you're going to try yourself with a file and advice from savants on the internet? Good luck man.
Funny thing Cherry Bomb, I've restored 12 Vintage Mustangs, two Vintage Chevy Trucks, built a dozen or so quality muzzleloaders, and have been tinkering with handguns and rifles most all of my 52 years. Oh yeah, I also restored five vintage and antique aircraft back in the day. What I've found out in my life's journey is that there are a lot of folks who possess the skills to be professionals and never become one, and then there are a lot of folks who become "professional" who should have found a different trade (including mine as a former professional land surveyor, and now Christian Pastor). Before you rush to judgment, please realize that many of us learn from the internet, books, dvds, and sage advice of fellow gunlovers and experts. Also, be aware that for some of us, $200-300 is not "chump change", but represents two weeks groceries. We may not be wealthy, but we can still enjoy and appreciate a fine old double barrel. I've spent my life resurrecting old treasures and returning them to practical service.
In the future, perhaps you should read a little more here on the internet to acquire the knowledge you apparently lack, before you rush to judgment. Frankly, you've embarrassed yourself. We know it, you know it, and now you're attempting to rationalize your condescending behavior. I personally would appreciate it if you would refrain from further commentary on my posts when I am seeking advice from a group of professionals and fellow doublegun fans. You see, I am seeking knowledge and wisdom. You've not offered either.