I think that I have got to the bottom of why the 3’7″ wheels don’t fit. Jim certainly did discover the error but what I had forgotten was that I wasn’t using a production etch. Sometime ago when I planned the second Birdcage Van with side cotes I asked Jim if he had any scrap etches that contained the wooden duckets from the V4 kit. He duly let me have some and while making up the two V1/3 vans I idly cleaned and folded up the remainder of the etches that Jim has sent to which I added the missing bit’s from my V4 kit not really thinking too much about why the etches had been scrap in the first place because there was nothing obvious to see. Upon checking last night,  the production etches have cuts outs to clear the wheels.