Well I made it all the way through before posting anything. I am just about done with my UDS and will post pics when I finish it with some tasty pron.
One thing that kept irritating me is the use of "food safe". From what I've seen food safe just means they have a liner in the drum. I'm sure that liner isn't food safe when it's burned. The only real food safe would be a stainless steel drum. I think a drum that had food in it or motor oil in it would be fine after a good burn. I've talked to people that used old heating oil barrels as pig cookers after a good burn.
Sorry for the rant. I just had to say it.