Sidney is identified as a former soldier of the 25th Londons from the following entry. His medal card only mentions the 7th & 19th Londons.

BCMH Summer Conference “Volunteer & Reserve Forces” 18-20 July 2008

The Changing Character of the London Territorial Force 1914-18
The case of the 19th (County of London) Battalion, The London Regiment (St. Pancras).

By Charles Fair

[In part from pg.53]

Another 1/7th Londoner was Sgt Sidney Weaver whose career in the Territorial Force illustrates many points already discussed above. He enlisted in the 25th (Cyclist) Battalion London Regt on 21 March 1912 and was mobilised on the outbreak of war. He served with the 1/25th on the East Coast, then as an instructor with the 3/25th until the whole battalion was transferred en masse to the 3/10th London Regt. He went to France on 28 October 1916 with a draft of 300 men, and was transferred to the 1/7th Londons after three weeks in a base depot at Le Havre. He took four weeks 'reengagement leave' in May and June 1917. He was transferred (on paper) to the 1/19th when the 1/7th was disbanded in January 1918, though in practice did not arrive until 28th May since he was on attachment to the 47th Divisional Salvage Company at the time. He became Acting CSM on 28th August, and remained with the 1/19th until he returned to England for officer training on 12 October 1918. Weaver had thus served under four different cap badges of the London Regiment.

Acknowledgments to The British Commission for Military History 

Liddle Collection at Leeds University.