I don't presently have any pics of the inside, but here's how I made it:
1) Cut hole in bottom of pot leaving ~ 1-2 inch lip all around
2) Coaxed a charcoal grate from an 18.5" kettle past the steamer insert ridge which now rests on the lip I left on the bottom of the pot. The heat diffuser sits on the charcoal grate
3) Put first cooking grate on steamer insert ridge.
4) I forget the exact distance I measured for the bolts i added for the second grate, but you can see one of them to the left of the ravens logo in my last pic above.
As for the thermometer, I used a 2" River country from amazon. In hindsight, I kindof wish I had just skipped adding one since I now have and prefer using my remote thermometer.