This is a little confusing. The tune O PERFECT LOVE is by Joseph Barnby. There is a traditional hymn called “O Perfect Love” set to its namesake tune but this isn’t that one.
This is a paraphrase of Psalm 128(127) by Bernard Kirkpatrick and this time it appears he has put copyright on it. It is written for weddings.
I made a backing with the help of chords from Together in Song (it’s not that hard CWB II) but you need to get the lyrics from CWB II or Bernard Kirkpatrick himself.