This is the last tune of track 7 of Irish Times by Patrick Street https://thesession.org/recordings/786 .
It would be good if someone has another title for this, since there are already plenty of tunes here called "Denis Murphy’s". It is possible that it has already been posted under a different name, although an abc search failed bring up any matches.
I just played it into TunePal and it called it Murphy’s Scartaglen Reel. I looked up Scartaglen here and found it listed as P.J. MacNamara’s https://thesession.org/tunes/11180
Excellent sleuthing, Gary. It’s clearly the same tune, but a very different take on it. I’ll leave it to Jeremy to decide whether it warrants a separate submission or whether it should be added on as a setting.