Thanks - in fact the skewers go on the frame in the last picture in my opening post so they are proud of the grill bars. I think substituting the wider skewers will do the trick.
Egg would definately not be added - it's not the right thing to add. And in any event they full off before they would firm up. But the solution of wider skewers and a dryer mix by substituting chopped onion for the grated onion I'm currently using with a touch of crumb will do it. Thanks again for the suggestions.
It does thanks .... as I thought - I need to go back to the flat skewers. I must also use chopped rather than grated onion. That I think will cure it.
Thanks again.
I suggested eggs because I use them to stop hamburgers falling apart when you first put them on a grill - the raw egg binds, it doesn't have to be cooked to bind.