Hey WraithKenny, appreciate the quick response.
Worked beautifully, so when a v3.0 notice showed up in the Admin panel, I briefly read the changelog and clicked automatic install. Bam, the box containing the script was suddenly blank on every page.
The script isn't essential. It just makes the pages that include it a whole lot more useful, and its absence is pretty noticeable. Wasn't such a big deal to manually reinsert it. Which I did. The upshot being that I can't say whether the original scripts were gone for good or whether they can be restored.
Much as I'd like to help sort this out, I'm not a code writer by any stretch. No doubt there are others who might provide more useful input. Just thought it was worth bringing to your attention.
Otherwise as mentioned, Scripts 'n Styles is a highly useful plugin.