If you lift up the lever with the yellow sticker and push the handlebars as far forwards and downwards as they will go, is an allen key bolt head exposed in the stem?Okay here is the picture..
Maybe you could replace the whole unit with a conventional quill stem?If I lift up the lever it allows the bars to rotate nothing more and no forward travel. I noticed a plastic cover on either side further down the stem which I pried off,There are 2 screws under each which I believe if removed would allow the top part of the stem to hinge forward and give access to the hidden centre screw to allow rotational movement. all in all a big job for a routine action and one which I have no intention of doing twice every time I transport the bike,many thanks to the people who tried to help me find a solution.