Hi Debbie,
I've had a look at Montgomery Stevenson, by the looks of it most of the Stevenson's were coal miners,
your great Grandad was also called Montgomery Stevenson he married Elizabeth Fyfe or Killin she is down with both of these names on the marriage certificate.
Montgomery Stevenson (born 15/4/1871 Carluke, Lanark) and Elizabeth Fyfe got married in 1894 in Tillicoultry, Clackmannanshire, his parents were:
Montgomery Stevenson (born 24/8/1845 Kilmarnock, Ayr) and Jane (Jeanie) Johnston who were married in 1869 Dalserf, Lanark his parents were:
Montgomerie Stevenson and Rebecca George who were married in 1841 Kilmarnock, Ayr. I can't find anything about them at the moment apart from he was a coal miner and Rebecca had died before her son Montgomery got married.
Montgomery( or Montgomerie) born 1845 was their third child and first son.
Hope this helps
Hazel