Good news, Monica, I think I have found William's death in 1908. It's in Dunbar and he's listed as the widower of Margaret. It was registered by his son, also William so that would suggest the family stayed in-county.

In everything else, he's listed as a general labourer but he's now referred to as "Pensioner of regiment". Is there anymore details I could get?
I thought I had found her death using SP's new "mother's maiden name" feature but it was an 1850s death in Fife.

Dashed my thoughts of it being a good thing.
Added: I've found the family in 1891 and Margaret is still alive, claiming she's 40, when in 1881, she was only 38.

Going to try and find them on 1901 now.