I wait all day and night and he doesn't show. I fast travel away then back again, and he still is not there. The quest marker to return the crown points to the door of the fort in Solitude when I'm outside, but when I go inside the fort it points back outside. Wtf.

You play on PC? If yea you can use teleport command to fly to him or make him fly to you

He's not in his usual spot. You find him sitting outside the map room, as you enter. He's a bit hard to see.

Hmm, I'll take another look, thanks. If it's still a no go, what's the command to make him fly to me? Yes, I'm on PC.

You may want to check out how all work in http://www.uesp.net/wiki/Skyrim:Console

For starter on this bug:
prid 000198BA <--- This mean Select this reference ID. Reference ID can be found in character info of http://www.uesp.net/wiki/Skyrim:General_Tullius
moveto player <--- This mean move selected to you. i.e. teleport it to you

OR you can do this

player.moveto 000198BA <---- this one teleport you to him instead of him teleport to you

If he is not there for the crown he shouldn't get it. Go to Windhelm and give it to Ulfric.

Oh btw in general you should teleport to him instead

Oh btw in general you should teleport to him instead of teleport to you. It you make him teleport to him he maybe away for next quest triggered location