Hi Bella,
The postcard is definitely the Globe cemetery. There are two cottages in the picture, which would make sense.
The Globe viaduct was, as you rightly say, demolished in the 1920s. You may be interested to know that the stones from the demolished structure were recycled and used as part of the foundations of Gleneagles Hotel, Perthshire, which was built as the flagship hotel of the Caledonian Railway Company.
As for William's occupation being described as a labourer, he may well have retired and allowed to stay in his cottage rent-free on the condition that he still did some work in the cemetery.
If he was in the regular army he would have been in receipt of an army pension, probably about sixpence a day.
A "servant" sounds a bit of an extravagance in a little but and ben cottage, she may have been known to them and was a glorified lodger (with a small L)

Milsop is a local name, they all lived in the Milton St area, the street that leads down to the Globe.
Good luck with your research,
Lodger.