I agree, it is standing next to a Bel Royal on my bench, and the two are nearly the same. I posted as per the label, but also believe it to be BR and not SW.
Thanks all, I purchased 3 plants of St Swithin, 3 Bel Royal, and 3 roths as a single import some years ago. According to my records they arrived a bit jumbled. The plant is a bit massive to be a St S.