Here's another case of "Ranzo" being extended to show his benevolence, not his bastardy:

Hugh St. Leger, "Chanties," Black and White (July 2, 1892):

"...after a few more stanzas, we find him an excellent skipper.

    'Now Ranzo is our old man (Captain),
    Ranzo - boys - Ranzo.'

This lyric goes on to say that Ranzo was a captain who supplied his men with a generous amount of grog,...and the lines alluding to this trait are sung in a very pointed manner when the captain is near, on a ship where no grog or very little is allowed."