I will post but its going to be a while for the build as I wil be out of town for a month.
The drum will be Carbon Steel 10" dia schedule 5 yes 5 its .133 thick at the wall. I will go with a rear perforated for the air flow to go thru the drum during roasting as most all do .
once I get the drum welded together I will sqaure the front and back to the shaft then take a skim cut of the OD to make sure its concentric. to the center line of the shaft.
By my estimates this will be a 2KG roaster or a little bigger