Layout Chronicles; milling Homasote

I like handlaying my track. Particularly now with the Fast Tracks system which makes building turnouts a breeze.
One of the criteria then is for the roadbed to be capable to hold tiny spikes while being soft enough to accept said tiny spikes without too much effort. Which is where the old standby, Homasote, comes in.
Made from compressed paper fibre, it's dense enough to hold spikes without being to hard to spike into. It really has only one major drawback. It's filthy stuff to mill.
Now I like to mill a bit of a profile into my Homasote roadbed. Just as you see below.

When I did this for the old layout, I cut those rabbets on the table saw and then slit across the strip every inch or so, which would allow me to bend the roadbed do the desired radius'. I could do this at work where we had big machines and dust extraction.
No such luxuries for me now. Also the slitting required that I fill the cuts with spackle which added another step and offered up locations where the spikes wouldn't be as secure.
So this time around I'm cutting the roadbed into the desired shapes and milling rabbets into the edges to help get the ballast profiles I'm after.
The first step was finding the right router bit. Which turned out to be more of an adventure than I had prepared for. The right sized bit was found in the 5th store I went into.

With the bit in the router and the strips sawn, it was time.
Now let me caution you on the biggest caveat of all when doing this.
Do it outside with a mild breeze. "She who must be obeyed" will end your layout building career in a flash if you mill Homasote in the house. The dust is as insidious as the little white balls that come from sanding white beadboard. And there will be clouds of it!

With that done , a touch of sand paper to knock of the fuzz and we're ready to glue and screw it down.

8 feet down, 80' to go, more or less.
Before I paint the roadbed, which will seal it against moisture, I have to get that pesky backdrop up.
I have a plan and it's cunning.