Now, yah see it all works out.
I suspect I am of a size with ArkAngel (although I absolutely refuse to wiggle).
Got the yoke set up okay (with the aid of Batfinks instructions), but whoever designed these things need to understand that we don't all "follow the yellow brick road". So took gregorachs advice and added a set of extension straps. Result! Lovely adjustable, comfy fit. Photos available of how to stick it all together if anyone else ever struggles (although if you follow Batfinks instructions and figure the extension straps out for yourself it aint hard)
Red