Hey Rob, if you can't get hold of an older Mclaren chassis, you could always get a motor mount converter from long can shape (NC-2) into a Mabuchi shape (NC-1), so that you can use NC-1 motors in any chassis that accomodates NC-2, 5 and 6. I've done that for a few of my Ninco cars already and it works great. Hope this helps.
p.s. I'm just assuming you didn't know this already, so pardon me for mentioning otherwise.