Having disgested the various meaning suggested for bla, I have a couple of other lines which I'd love to have translated:

"For It's my daily fare an' as much'll pay my doss."

The only translation I can get form the web is that "Doss" is a pouch of tobacco, suggesting the line means that the speaker's roving is how he makes his living and keeps himself in tobacco. I can go with that, but would welcome other suggestions.

and

"For Scotland's greatly altered noo, I canna raise the wind."

It was suggested by someone that "I canna raise the wind" means "I can't get the breath." But that makes no sense to me, since we are looking for a reason to leave the "altered" Scotland for "Paddy's Lan'." The only meaning for "Raise the wind" I can find have to do either with witches actually raising up a storm or with braggarts raising a different kind of wind.

Greg