There is a literal (not a metrical/singing) translation of the refrain and three verses (vv. 1, 2, 6) here.

Similarly, there is a literal (not a metrical/singing) translation of five of the six verses (vv. 1-4 & 6, but curiously not of the refrain) in this Vatican Mass booklet.

Finally, there is a very loose (and somewhat verbose) translation of the fifth verse here — search for the word "beatam" and you'll find the fifth verse (Latin, in italics) followed by its English paraphrase.

My recollection is that the 1964 Peoples Mass Book (published by what was then known as World Library of Sacred Music) had a version, with perhaps the first line of, "Holy Mary, Mother Most Merciful." I have not found this online. I am uncertain how many verses there are, and I seem to recall that it is more a paraphrase, rather than a strict translation.
The Richard Proulx version only has two verses. https://www.giamusic.com/store/search?elTuneName=salve mater misericordiae
The Pius X Hymnal (Marier et al) has two verses (perhaps the same as the Bragers... English by C. J. McNaspy).
And then there is this, which honestly says that it is a new hymn https://www.redemptoristsesker.ie/2017/01/salve-mater-a-new-hymn/
A public domain accompaniment is found in the Accompaniment to the Justine Ward Hymnal https://books.google.com/books/about/Hymnal_Accompaniments.html?id=Sjj2OTP2G4AC

@oldhymns
A literal translation of the refrain and all six verses can be found on pp. 96f of Adrian Fortescue's Latin Hymns (pp. 54f of the pdf).