Ours is a late UK one in white.
he pipe came detatched from the manifold because the end had hardened and cracked. At present I have taped it and used ajubilee clip to secure.
Not aware of any restrictor will look at workshop amnual. Tried a piee of new pipe, slightly smaller bore, and the terrible running continued as if the pipe was not fitted. Seems that it is very sensitive to pipe bore / length.
Thanks for your comments.