Yes I have to hinges but can I fit inside on the cross bars bearing in mind the gap
Got them. I need to now if I fit in the cross bars or not. Bearing in mind gap athe end of bars.
About 6/7mm. I think it's to allow you to cut the door width down if required to fit the frame.The hinges would normally go on the cross bars (ledges) and the back of the cross bars would be inline with the inside of the frame in the room it opens in to if that makes any sense.
Not sure about the gap you mention, are the ledges shorter then the width of the door, the photo is a bit blurred.