Just a short update to my previous post, I got a chance to check the local press in Derry, Derry Journal, Londonderry Standard and Londonderry Sentinel for an obituary or death notice for William.
The only reference to the death I could find was a small paragraph in the Sentinel:
SUDDEN DEATH
The Death took place suddenly on Thursday morning of Mr William Meredith Miller, only son of the late Sir Henry Miller, a former Mayor of Londonderry, and for many years Town Clerk.
The death notice may have been in the Belfast Telegraph, Newsletter or perhaps the Strabane Chronicle, I do not have access to those archives.
Regards