Hello Sue,
Not sure whether this will hep.
I was curious and, looked up the Dumfries & District Post Office Directory for 1911 & 1912. Only found a Matthew PAUL living in Greenbrae Loaning (drain contractor) no mention of Bethel Cottage, though.
As akc mentioned, there is a Bethel Cottage in Greenbrae Loaning. Had a look at the Google maps. I remember the cottage, as I passed it every day, going to primary school.
cupcake