Wish I knew more about this publication, but a Google search reveals that a dime novel about pirates called "The Steel Mask; or, The Mystery of the Flying Cloud. A Romance of Sea and Shore" was published in May, 1899, as No. 1024 in the series Beadle's New Dime Library. The author was J. H. Ingraham, a prolific writer of such tales. The story had appeared earlier (site doesn't say when) as No. 93 of De Witt's Ten Cent Romances.

May be of no significance except as more grist for the mill.