I haven't checked my PM yet but I should have your address in my PM box over at JRCBD.
The production MM .18 had the header and pipe going alongside of the radio box where the prototype used this header to go over the top of the box so it'll be more like a wrap-to-center setup.
Remy had a mix of parts on the prototype including a CEN Racing .18, the reason why you see in his ads a different paint job and .18 on it.
I've got shots of the original somewhere.
Another possible header is one from Traxxas that I've used on my .12 monos and a 'rigger.
I'll send it to you so that you can see if it'll do the job.