An adjustable sear would be nice if anyone knows who sells it.
The Brooks kit acts as an adjustable sear (sort of).
There are two small tubes, one .014" thick and the other is .018" (wall thickness of the tube).
The instructions clearly tell you how to install them. You only use one. If your sear engagement is too much or too little, you try the other one. I think they are worth the low price.
HOWEVER, I read on that other forum that in some people's guns they are both too thick or both too thin. This seems rare. A lot of guys love them.
My personal experience; The thickest one drastically reduced the sear engagement. BUT being the tinkerer I am, I made another one on a lathe with .021" thickness. It took ALL perceivable creep out. But just to make sure, I went back to the lathe and made one .023" thick. NO sear engagement!
So now I use my homemade one of .021".
It crossed my mind to make a bunch of different sizes and try to sell them. BUT I am concerned about liability. This is serious stuff. When you get your gun sooo close to the ragged edge, some day it might just go off. And when the investigation is over they blame it on Feez's tube that was defective. So I recommend trying Brook's kit and if you're not satisfied, find a machinist to make one, but tell him it's for your antique clock.
http://cz452.com/