The lyrics of the De Masran song sheet given above are idenrical to those on sheet music, "Carry the News! We Are All Surrounded," "as sung by Simmons and Slocum's Minstrels," published 1870 by R. Wittig, Philadelphia. The same authors are given; words by Charley Howard and music by Walter Bray, with the additional note, Arranged by Eddie Fox. In other sites, the song is referred to as a "minstrel walk-around."
A search for "We are all surrounded' turned up the chorus in lyrics of "Sea of Angels," by the group Plus One (singers of Christian songs). The phrase "Sea of Angels" is from psalm 103:20-21; song not found elsewhere. The chorus:

We are all surrounded
Swimming in a sea of angels
We are not forgotten
And we will win
Because you send your angels.

"Carry the News to Mary" appears in "1000 Fiddle Tunes," Cole, 1940. "Ryan's Mammoth Collection of Fiddle Tunes," first published in 1883 (still available, publisher Mel Bay), and other collections also have the song.
J. J. Haman published piano music in 1871 with the title "Carry the News" (Lee and Walker). At American Memory.

Liner notes on western lingo by Johnny Cash in "Sings Songs of the True West" define a horse as "Carry the News to Mary;" this does not appear in Adams or other books of western words that I have seen.