Doing the square doghole in the vise jaw posed several "challenges" (read "now how in the hell am I a) going to balance everything on the end of the vise jaw which is only 2 1/2" thick, b) how am I going to have enough meat behind the dog when the jaw is only 2 1/2" thick?", c) "how am I going to route a dado that's going to be almost 2 inches deep when the dado bit isn't long enough?" and d) "how am I going to fill the open end of the dado?").
The balancing act problem was solved by merely clamping some thick stuff to to the sides and aligning the top and the front edges to the vise jaw. Slipped the template on and held it on with four brads. By moving the "hole" to the very front of the jaw and having the "step" in the removable face of the jaw, challenge "b" was semi taken care of. Challenge "c" was solved by finally finding the 1/2 inch Onsrud two flute spiral bit I looked all over hell for when I routed the dogholes in the inside of the apron. And it cuts SO much smoother.
Here's what I've got now. The open end of the "hole" needs filling.
A "cap" in a contrasting wood, maybe walnut. padouk or rosewood, glued and pegged with a light colored wood - maple? This'll be a great excuse to go rummaging through the boxes of cut offs of exotic woods I've been picking up here and there for the last couple of years.
Here's what I have in mind.
And here's the details and the wood options.
The initial end cap idea turned out to be more complicated than necessary. This one was far easier to do and worked,