I just re sighted a SS .44 Special Flattop last night. Lots of work, but looks like a factory job. Hamilton Bowen's outfit is currently the only source I know of for a sight blank that can be made into a patridge blade and then pinned into the existing sight base.
Just be advised that the blank is VERY oversized in every dimension. It's overly long, tall, and wide, which makes it adaptable to various forms and applications. I had to remove over 0.005" from the width, a lot off the length, and a lot off the height. Then I had to quarter round the front, put a very slight undercut to the rear(less than 5 degrees), a slight slope toward the front, and then polish and cold blue before installation.
The pin on my gun was a spiral pin that mic'd just over 1/16". The pin hole in the base was a perfect 1/16", so I used that bit to cross drill the sight tenon once it was in place. I strongly advise against using an electric drill for this, as it's just too delicate. I use a jeweler's drill I bought on the net. Drill half way through from one side, and then finish up by drilling from the other side, so that you don't screw up the hole in the base, which you will almost surely do if you go all the way through on one pass.
A belt sander with table and belt brace are a real life saver in shaping once you square the table to the brace, but I do the thickness reduction by hand on a surface plate with 150 then 1200 grit black oxide paper. Thickness is just too critical for power tools. Not easy, took be just over four hours with interruptions by wife, and neighbor. The hand fitting on surface plate is the worst time consumer.
Sorry, no pictures. Wife got her hands on the digital camera, which predictably suffered a violent demise. No mechanical aptitude.
My SS Bisley .45 convertible is next after I let my sore fingers have a rest from all that time slimming the sight on the surface plate.