Normally for the intake manifold, you replace the intake manifold. That's around $650 in the US which is a Pierburg. There are other repair kits you can buy which just fix the lever or rods depending on what's broken, but the flaps eventually break and end up doing engine damage. If you replace the manifold, you should get the same or more miles out of it, I think Pierburg might have changed the design of the flaps so they last longer. From memory, I think you're fine on the engine number but there's a long thread on here about the balance shaft and the exact number is mentioned in that thread, I think it starts with a 4 and yours starts with a 5.