I myself would have no problems with the organ and choral music of Herbert Howells and Healey Willan being used, with the only modification being omitting the Filioque. In fact if a WR parish committed to using them along with standard Gregorian chant exclusively, Id go. Of course Ralph Vaughan Williams and the choral anthems of Samuel Sebastien Wesley are most exquisite. Actually the entire Anglican musical corpus is IMO mostly usable, and where it isn't, its fairly obvious. Even in the hymns of Charles Wesley, John Wesley was secretly ordained a bishop by Erasmus of Arcadia, probably, in 1763 (he refused to deny it without confirming it in the 1770s, had he admitted it, under the Praemenuire Act he would have been liable to decapitation as an Anglican cleric), and advocated something fairly close to Orthodoxy, differing primarily in his heterodox views on baptismal regeneration and his Aldersgate experience which could be viewed as prelest. But, he still apparently had uncanonical episcopal status as an improperly ordained Greek Orthodox bishop, and with this in mind, he edited the hymns of his brother, setting aside those he viewed as doctrinally unsound. And as for what's left, well, Christ the Lord is Risen Today for example is so obviously Orthodox that it was sung congregationally following a Tridentine mass I attended on Pascha Sunday at 1 PM last year.
And if the Latin Mass Catholics, who are pretty hardcore, will sing it, it has to be usable as far as we're concerned.
I take a liberal view when it comes to Western church music just as I take a liberal view of the Western Church. While I recognize the Orthodox Church as being the One, Holy Catholic and Apostolic Church, I do not regard Western Christians as accursed heretics but simply as the victims of an evil Frankish Emperor and a power hungry Pope, who subjected them to centuries of dogmatic instability and denied them access to the Truth entire. But they could not Ron them of that knowledge of Chrost once taught, and I interpret the Protestant Reformation as being a misguided and misdirected rebellion against the heretical excesses of a corrupt Rome. But we can determine which parts of Western Christianity are worth salvaging by evaluating them in comparison to Orthodox equivalents, and I think we will find most of the Western Rite in its Roman, Mozarabic, Ambrosian, Carthusian, Dominican, Sarum, Anglican, and Swedish Lutheran variants, remains usable with minor cleanups, alterations and restorations.