Haven't seen our visitor since Saturday so it may be that s/he has resumed his/her migration south. I have a band number and I will keep an eye on the "lists" to find out who they were and where they were from. If the band doesn't turn up on the "lists", then I'll start contacting the gang for assistance.
Will let you know what I hear, when I hear it.
And if anyone sees her/him on the building over the next little while, be sure to post it here, I'd love to get a few more chances to look at that band ...