Hammer,
First, it is only adjustable for windage. No way to make one adjustable for elevation without some major machining, and it is pretty easy to fiddle with different FA front sights.. I use hand tools. And it is pretty much a one way trip for the base. And I had to "mill" (file) another cross slot at the front of the base to have any hope of getting rings to clear a scope's turret area.
Basically, I milled a slot in the back of the mount, perpendicular to the mount, the width of a j frame sight tang, top down, the width (front to back) of the last rail portion of the tsob base. I then drilled a hole in the j frame tang and the tsob base for a small screw. I then used Brownell's Accragel (glass) in the slot, around the screw and tightened everything down. Once everything set up, I filed the top screw head flush with the top of the base, and bead blasted everything. The last thing to do was to cold blue the tang that is milled into the base. I used the black dye with the accraglass, so it all actually looks pretty dang good.
As my gun is only 4 3/4" in length, I also cut the front of the tsob base right at the front of the frame, even with the part of the frame that accepts the barrel. This allows me to use FA holsters that are cut for their red dot sight base (I also have one of these).
My first iteration was with a 1911 sight, but that did not hold up, as the tang on the sight was vertical, and I pinned it in from the side. I also tried black moly resin on the whole affair, but the quick release rings of the various optics tended to chew into the moly resin paint, looking a little like heck. So the beadblast back to silver for the entire tsob base, with the rear sight and the portion of tang (blued) milled into the base looks pretty clean. I have another tsob base that I may play around with, but I really to need to hit a gun show of some sort so I can handle various rear sight assemblies (Ruger's, larger Smiths, etc.) I'd like to pick up a larger rear sight, perhaps one that I can find different blade styles from some place like Brownells. I need a sight with a tang that comes into the center of the rear sight assembly, as opposed the J Frame sight which comes in to the top of the sight. This would allow me to mill a slot from the back of the tsob forward, then I can pin it with a roll pin from the top of the base, to give more support for abuse.
This first attempt was a proof of concept, and the J frame sight has held up to several hundred full throttle loads, so I think I am good to go. It is kinda interesting to be able to switch from a scope, to a J Point, to an Aimpoint or use irons, with no mods to the gun.
Craig