Is this my elusive Gt. Gt. Uncle

[chempat]

This death is worth considering if he died just before his birthday and was registered a few weeks later:
   Duncan M Macleod
Birth Date about 1876
registered December quarter 1932
Age at Death   56
Registration district    Wakefield  Yorkshire West Riding
Volume  9c  Page   97

[Jebber]

The Duncan who married Lucy ALLEN is the wrong one, he was the one born in Mile End in 1874, not Liverpool, it states it on the Naturalisation paper.The paper also include one for his wife Lucy.

So I am afraid the marriage certificate will be of no use to you,

[Michelle56]

Ah well, not to worry.

Anyone want to buy a marriage certificate, (half price).

[Jebber]

This death is worth considering if he died just before his birthday and was registered a few weeks later:
   Duncan M McLeod
Birth Date about 1876
registered December quarter 1932
Age at Death   56
Registration district    Wakefield  Yorkshire West Riding
Volume  9c  Page   97

This may well be his death, but it would have been registered within five days, unless there had been a problem requiring an inquest. Anyway ages on death registrations are notoriously unreliable, the informant was not aways sure of the facts.

It is a shame you were rather too quick on the draw in ordering the certificate, I know it is tempting to dive in when you are desperate for results. It is always worth taking a little time and try to make further checks first.

[amondg]

Ref ancestry.com Outgoing passenger lists.
11 March 1908 S. S. Empress of Ireland sailed from Liverpool to St John, New Brunswick Canada
Arrived 24 April 1908.
Passengers
Duncan Mcleod age 32y 10 months  Clerk born Scotland
Lucy McCleod born age 22yrs 11months  born England
Duncan McCleod age 10 months. infant born England
Purpose visit sister Alice McCleod in Spokane Washington.
Address in England 55 Wanstead Park Road, Ilford.

[chempat]

Think this is that Yorkshire death, so rule him out also:

https://familysearch.org/ark:/61903/1:1:XWVG-XWC

[amondg]

The death certificate dated 14 June 1937 in Takoma Washington for the Duncan McCleod  who married Lucy states his parents are Duncan McCleod and Emma Shelley. His declaration for citizenship gives DOB as 11 June 1874 and name as Duncan Allen McLeod.

There is a Duncan McCleod born 11 September 1875 (transcribed) could be the 19th, who is listed in the Royal Naval Volunteer Reserve Service.
Service number MC687
Division London
The year 1919
The original is at the National Archives at Kew in London. 
Might be worth a look.

[Michelle56]

Duncan McLeod was originally in The Royal Lancaster Regiment, his attestation papers state he enlisted on 27 October 1893, Soldier No. 3965.

[amondg]

When was he discharged from the army?
Did he serve long enough to get a pension?