OK well Rory didn't tend to do too much in the way of full instrumentals as I recall, though some of his songs had decent instrumental/blues breaks.
Here's what I've found so far.
If I come across any more I'll let you know.
Incidentally, don't want to sidetrack the thread, but if you like long, rambling guitar instrumentals, can I assume you've made the acquaintance of one Gary Moore?
Let me know if not...