Well, that is very interesting. A reference to a convent is interesting given that the song is from the Armagh area.
Maybe the 'dandy cap'was stolen during the plundering. That last verse is so strange, as if everything is totally normal again. Maybe the only sign that the dream-like plundering happened is the fact the Michael has taken his "dandy cap" out to look at it in the sun.... hmmmm. Its like a mystery. I don't think cross-dressing was the intent of the lyric.
Thanks for the thoughts.
Claire