While touching up the paint on 31466 I spotted a fairly major error on my model. As shown on this photo https://www.flickr.com/photos/rob50037/14130188312/in/photolist-qKrSUb-e27H2q-nwU7bv-nwCUGq-n52kF3-nwVnBN-EgNpme-e4Yhgz-c5Qep7-eik48S-igPgGh-G29o5a-nVVN6n-caKyFY-nJ8qxB-nfpusb-oPXQAH-eisD8D-og5nET-WjH99W-qSd78m-5qLUm9-eiGvPy-YAafUV-dcLXLj-nVF1Kv-nXWWrh-nEYmAL-c7MJrS-c5Qr19-eiyXe9-ecM9iA-c6ufXy-nW2Vu9-Zsr3KJ-oRWpvZ-qFferr-Uu7Cgx-qwcwdR-r2HXoP-Y95b5Z-qPdgr7-fB84CE-r2UJNa-rNYyYz-nnF8Vh-rvKaKX-fB86wN-akm5gX-nka3Fs the bodyside grills under the radiator fan have been modified.

It looks like the cross piece between the two grills has been chopped out and an additional pipe added (which I guess is just hidden on the normal grills.)

So with half an hour to spare thanks to work being closed for the snow, it was out with the knives.

After pushing out the two grills I carefully cut out the cross piece. I also cut off the flange around the side of the grill (top / bottom) which would have touched the cross piece.
A piece of 10 thou was glued behind the two grills, then using some evergreen offcuts and some handrail wire I added the pipe and it’s support brackets.

Now I just need to repeat for the other side...

Photo taken before the two final bits of plastic were added.