I loaded the board design into the 3D viewer to see what it'd look like in there.  The 6551 wasn't showing up because the selected model was for a socket and the model wasn't present.  No big deal...change it to the proper 28-pin DIP and it came right up.

I then noticed that the edge connector was showing up gray instead of gold.  The paste layer was enabled for the pins.  After fixing one pad in pcbnew, I loaded the file into a text editor to fix the others.  Told pcbnew to reload the footprint, went to the 3D viewer...edge connector's now gold, as you can see in the renders.  Shiny!

Except for 6551s, I think I have all of the parts on order.  For the first build, I'll probably just desolder the 6551 from the old-version board I built up a while back.  These ones will be built with sockets to avoid the need for desoldering them in the future.