I would like to publish a possible prayer - no not to GKC - but for his canonisation - and for his wife Frances. It's not approved, and cannot be used "publically" - there are actual church laws about this sort of thing - we must be very careful not to violate them. (The main idea is not to anticipate an authoritative decision - that's up to the Authorities... but you're read Orthodoxy, so by now you ought to know all that by now.)
Perhaps another day I can go into the matter a little more deeply, but for today, here is the prayer, which seems very appropriate for the feast of the Most Holy Trinity:
Prayer for the Canonization of G. K. & Frances Chesterton
(for private use only!)
Oh, Most Holy Trinity, in the union of Frances Blogg and Gilbert Chesterton in Holy Matrimony, You gave us an example of Your own Trinitarian love and revealed the supernatural fruitfulness of Christian marriage. You enlightened Your servant Gilbert with great gifts of mind to defend the One True Faith, and endowed Your servant Frances with many gifts to be his loving, patient, and devoted wife and trustworthy support. If it be Your will, may the Church recognize the sanctity of this married couple, modelled upon Jesus Christ the Everlasting Man, through Whom we pray. Amen.
Mary, cause of our joy, your servants Frances and Gilbert acknowledged you to be the Virgin Mother of the Incarnate Word. Through your intercession, may the Church soon acknowledge their sanctity.