Something that I didn't do originally is to trim the battery leads - comparing the photos, you can see how much excess there is. This makes re-assembling the watch easier as there is less excess wire to tuck away and find space for.

I also didn't get a photo of the battery just on its own, to show just how long the leads are, but they're about 3 or 4cm I'd say. In terms of the length I ended up trimming them to, it was approximately 1 length of the top of the battery (the yellow taped portion in the last photo).