I see it also has a hand pull start. Try all the other things I suggested and then try the hand pull. A diesel engine is very powerful so pull gently to take up all the slack, then one almighty pull as hard and fast as you can. You will need to do this at least three or four times, or more as the first few pulls just draw the fuel though the system.
Let us know how you get on.
Dont forget never let diesel engines run out of fuel or they get air in the system and then wont start and need to be bled, which eases the air out of the system.