Just bumping this up as it's suddenly very relevant due to IRM's new NIR coaching stock!
Is it fair to assume from @hexagon789's post that all three locos, 111, 112 and 113, had yellow panels by their 1989 and 1990 re-paints?
So they went from red panels to small yellow panels to large yellow panels to small yellow panels?
Here's a photo of 112, dated 27th May 1990, courtesy of Adrian Nicholls on Flickr, presumably just before repainting with yellow panels?
And another of Adrian Nicholls' photos, showing 113 on the same date, deep blue with small yellow panels: