In the final episode of this build, I fitted the approach tracks for each quadrant of the crossing. In each quadrant, one rail uses a standard rail joint and the other extends to, but does not quite meet, the frog.
After test fitting, I glue the track down with my usual technique using clear caulking. I also filled the crack around the crossing base so it doesn't become a "black hole" for ground cover later. The photo below shows the last of the four quadrants being glued down.
The next big test would be to apply power... would there be any shorts? I flipped the switch, and no unexpected chirps from my Digitrax command station. Success!
The next test would be to see how well locomotives would navigate the crossing. I didn't waste time and went straight to steam. I put a Broadway Limited Imports PRR class H10s 2-8-0 consolidation on the rails. To my surprise, it not only passed non-stop through the crossing, but was able to do so at a creeping speed!
The project is complete, with thanks going out again to Dave Trone for the instruction on how to scratch build track. May need a new customer on the layout -- Trone's Frog & Switch!