I have started and shown hundreds of works on blender artists forums.
I have however, only completed one, a piece which i have used in comercial work for a website:
C+C appreciated
What do you think?
I guess the modeling is fine (I don’t know what it is).
But no materials, no lighting to speak of, no ground … it doesn’t look finished.
I came in here with the thought: “oh boy, what’s this gonna be”.
My thought, was confirmed. Then the first thing popping in my head was: “Wait a minute, is this the W.I.P. forum?”
haha, Ok I had my fun. Been watching to much south park.
Your model is fine but you honestly can’t consider that finished now can you?
maybe try greating a skere but putting it in a house, maybe an abandonned bureau might be a good idea.
No Hard feelings riight 
Best of luck. Jacco;
Give the bottom part of the grenade ( i think it is a grenade) a texture that looks like a label for a can of brown beans. And write "Uncle John’s Gas Bomb, Made in the old fashioned way! “Ready to eat in two minutes!” “The smell stays forever…” It would be awesome.
And give the rest a texture.
Then, make a scene.
After that you can call it finished. Right now it is just a mesh without any meaning at all.
I really don’t intend to be harsh so forgive me if i was.
Considering it’s his first project he’s ever considered completed, I’d say it’s pretty frickin complete. Let him get better at technical work before you bash the subject matter. I made worse stuff when I was starting.
Thats a nice model except it’s hardely finished. Add some colour and texture, then you can call it finished.
-FD
Not finished, need texturing, and rendering. If you were just modeling post in the modeling section of the forum.