I would have said both the Blackletter copies, Child A and B, were very likely printed in London first. The fact that the added chorus is loosely in Scots means very little. The rest of the ballad is in standard English of the time and in the 17thc very little if any ballads were printed outside London. The fact that A was bound up with an Edinburgh piece means very little as does the Scottifying of a few words in B. I can't remember seeing any ballads from Pepys, Euing or Roxburgh (17thc) that weren't printed in London.