More photos of the progress.

1) I received the top and bottom ribs about a week ago from Tom Ondrus at Crown Press. I've been busy since, configuring them to fit. This photo shows the bottom rib, shortened to required length, tapered, and bent down so that it will fit under the forearm. I have drilled, and tapped 6-48, a hole in the spacers at 6" and 12" behind the muzzles, to accept anchor screws for the rib. Sling swivel base has also been installed.

2) This is a view of the same from above.

3) Another view from above. The small block at the right is one that I filed up, silver soldered to the inside of the bottom rib, and drilled and tapped 4-48 to accept the mounting screws for the front sling swivel base. The bottom rib is probably thick enough to hold them on its own, but I wanted to make sure that the installation was "bulletproof".

4) Another close-up view of the bottom rib. When everything is set, both ribs will be soldered in place with Brownell's Hi-Force 44 solder. I still like my system of using these mounting screws to anchor the rib to the spacers. They act as a jig to hold things in correct alignment during the soldering process and they act as a fail-safe down the road, ensuring that the bottom rib does not come loose under the stress of carrying the rifle on a sling.

5) Here is the top rib, reconfigured somewhat from the way it was received, and sitting atop the barrels so that I can take some measurments for fitting.