Now certainly you could make something with those parts ..... But a few cations and a bit of advice first!
NO PAINT ON THE INSIDE !!! Really no paint ! What ever you make to cook / smoke food in you want no paint!
Now back to making a smoker......
You could put the parts together in all manner of ways and make something you could call a smoker, granted. There will be many that offer suggestions of how they would do it and why - and I bet they are all right
But one question, since you are just starting to smoke, do you think a one off contraption is the way to go?
Let's consider your fist butt.... It's got you feeing a bit uneasy about how it's going, perhaps temps are all over the place! No problem you say, I ask the Breatheren.... Now because you have a one off smoker you will get answers that conflict confuse and bewilder , all of them right in one way or another .....
If you build a mini UDS you know have a device that is well known and a huge knowledge base at the brethren - you questions will get answered with fire control, air management , and more targeted to you method rather than your cooker.
I highly suggest you build a UDS mini or otherwise and learn on it
then spread your wings if you must and build something custom
Really a small drum welded to a small air tank = COS which can be picked up for @ $100 at Wally World I'm sure welding and finding parts like grids etc will cost you more in the short run to build it.
Bottom line make a mini UDS with this drum or get a 55 and build a full size - you will NOT regreat it
Just my 2 cents
Hook Line and Sinker
Viking 30 inch Gravity Fed Charcoal Smoker
Brinkmann 5 burner gas grill with sear & rotisserie
UDS's 3 and growing
Char Griller w/SFB w/mods
Charbroil 7000 Gas Grill