Thanks.
I think that by using Save As instead of Save, I broke the path back to C1.
So, I now have a PSD in C1, with no PS edits applied to it.
I can do one of two things:
1. I can point C1 to the Save As folder and make it see the PSD file (with its edits) there. But, now I'm away from the original file.
2. I can drag or copy the edited PSD file from its Save As location to the folder of original images.
Both of these solutions annoy the pedant in me!
I'm simply wondering if, while still in Photoshop, it's possible to fix the mistake I made and re-establish the path to C1 with edits intact? File/Save (having already used File/Save As) doesn't seem to achieve this.
Thanks again.
D.