Porch skylight

Skylight is done. This is actually a very cheap unit. I got it at Yardbird's clearance for $47. It's double-domed (dual glazed) with welded corners and a deep skirt, so not too shabby.
At the contact seam (against the tiles) I laid a bead of Henry #209 Elastomastic and sprinkled some matching Decra granules. Hopefully it won't wash away too quickly!
The counterflashing skirt was custom-fit, and, needless to say, required nothing but careful craftmanship, aided again by the cardboard mockup technique.
Underneath are similar contour-fitting flashing pieces sealed with the elastomastic. The one-inch dam created all around at the folded edge should hold water from leaking below, which is actually not a big deal because the Grace underneath is the primary waterproofing measure.

Also visible is the white metal drip flashing. It's nailed on top of the 2x6 curb over the Grace. The bare wood on top of it is the two more inches for proper skylight attachment. Next time I'll use 2x8.