Anyone help with a Technic Oven?

I have got a Technic oven but no instructions/manual. The model number I think is A28-893550 and Type is E842439. The tenat has taken it apart inside to claen but not put it back together. There appears to be some kind of grill shroud/plate that is now just sitting inside but looks as though it should go somewhere. Can't find any mention of this oven/manufacturer online. Any ideas anyone please????