Have you got the wing removed Will? I replaced my inner wings nearly 20 years ago and I'm afraid I have neither good photographs nor memory, but I don't recall having too much difficulty in getting the steering box off. I suspect I would have removed the box covering the lower UJ first, then undone all the UJ bolts before removing the steering box.
One problem I did encounter that I wasn't expecting was that the new stainless inner wing was subtly different from the old mild steel wing, and it meant that although it mounted to the chassis fine, it took a great deal of fettling to get it to line up with the wing, and the centre section of the steering column needed lengthening a bit. Thanks to the bonnet overlap it looked fine from outside, but I didn't get a properly clean alignment betwixt wing and inner until I put the fibreglass wings on a few years ago.
