Got a "new" Low Wall the other day in 38-40 (38WCF), serial no.81425, but the front sight is so thin and shiny, that, even after having cataract surgery, I find it hard to pick up through the original "buck" sights. Took a front sight from a  slightly later serial no. Low Wall ,but much thicker, with the intention of swapping them over. It was easy to tap the "donor" sight out , but gave the 38-40 foresight a couple of taps , and no movement. The thin blade is about an inch long, and sticks out aproz 1/4" in front of the base and about 5/8" behind it and my question is, "Is it inlaid into the barrel, or does it sit above it?l would appreciate any help, d.

Got a Low Wall, older than yours and the front sight fits in the Factory Dovetail.  I can suggest 2 things to try.  Heating it gently with a Hair Drier just enough for water to hiss when you touch it with your wet finger.  Then a bit of Penetrating Oil with light taps.  Considering it has been together for a long time a few days of heating, oiling and tapping may be just what it needs to loosen up.  Wish there was something that would work on my old joints  .  Good luck.  David