Well, the line in question cannot be "a shilling from the crown" because, as Dave Hunt has said, the entire verse says, "they kindly did invite me to a flowing bowl and down they advanced me some money, a shilling from the Crown." That is, the line in question rhymes with "a shilling from the crown".

Dave, are you saying that this is two phrases, one being "they kindly did invite me to a flowing bowl" and the other being, "and down they advanced me some money, a shilling from the crown"?

That makes pretty good sense although it seems a bit awkward. That's the best explanation so far.

Bev and Jerry