Yeah don't think they are available but there are similar copy's out there by companies like DEESTONE, I run a old set on my Jeep and I very much agree great off road and very loud on road which is fine as it never see's the road.
"A true enthusiast, the M1 followed him during his incredible career that brought him and the M1 to almost every continent. South Africa, New Zealand, Mexico, Arizona and eventually Miami."
We're clearly the best though as it still has our sticker