I'm glad you think the chip might be salvageable after all - I did get a couple of spares just in case, but rather not have to throw any out.
Less glad to hear "back at step 1", of course...
I did not swap them, no, and now I wish I had brought my Arduino stuff with me to work today, but I did not, so I'll have to wait for either tonight or tomorrow to test that. Apologies for the sluggish pace of working through this, I just have my primary workspace at home (despite this being a project ultimately for work), and I don't always bring my Arduino stuff with me if I don't foresee having anything to work on.
I'll give the wire-swap a go at my next opportunity! Thanks for your patience!