Peter Warlock, Fantasias by Purcell

[homerdundas]

Arranged by Peter Warlock (Haseltine) (d.1930)
Edited by Mangeot, André (1883-1970)
originally: London : J. Curwen, 1927.
Reissue: Boosey & Hawkes
from Worldcat:
"Transcribed from the composer's autograph manuscript (British Museum. Add. MS. 30,390)."
--

Hawkes Pocket Scores, no. 58.
Plate no.: B. & H. 8840.

I guess USA is still copyright, but would the editor's contribution count? It was published before Haseltine's death - presumably the editing was under his direction.
Thanks.