Well, I had to move where the wood stove would sit in the cabin. Where the previous chimney was placed didn't make sense. In that spot, instead of trying to remove the flashing, I put in one of those tube skylights. Here is the pipe coming up through the hole, getting the roof brackets put on:
Once I got the cone flashing on (much harder than expected, as it seems the 10" cone is NOT really designed for a 10" double wall pipe) I did the collar and lots of extra goop on all the screws and edges. You can see the original chimney with the skylight in it in the background.
The final chimney is straight (I seem to have leaned when taking the photo) and is made up entirely of parts that I already had, or were part of the original chimney. I might put side brackets on, but this system is already pretty stable. The bricks nearby are just to hold the shingles down while the roof goop dries.