The current bridges are greatly improved over the original design (called channel bridge). Originally there was no stabilizing pin in the saddle, the saddle rested on the bottom of the rough channel. These were made before we had the means to machine the metal here, and used standard stock available at any metal house.
There are several problems with the design, which is why we improved it. The current bridges can also be plated, where that's not possible with the channel style (and still have it function). The newer bridges have more intonation throw as well. Channel bridges used a variety of fasteners, including some large black plastic nuts, we now use tidy aircraft fasteners. The intonation screws used to be slotted - kinda dangerous to the top.
On request, we make a decorative channel bridge now, but using the stabilizing pin and intonation screw, and the saddle does not contact the bottom of the channel. If I run across one, I'll post an image.
