The ailerons are quite fiddly to build up unless a simple jig is used,to do this drive three nails into your workbench and offer up the brass leading edge,place a couple of nails behind this to hold into place,next offer up the Mazak tip ribs and place small wooden blocks behind each one and hold with a small nail,now thread the inner brass spar through the centre,trim to size and add the remaining ribs and the small root spar,now spot glue the joints with thin cyno,capillery action will do the rest.Allow to dry overnight remove from the jig and then re-inforce the joints with slow drying araldite.