Davidhall,
On the 30th August 1918, the C in C of the British Forces in Italy awarded decorations in respect of "exceedingly gallant work in the recent raid". Amongst those decorated was 18061 L/Sgt W. Whitlam - Military Medal. As perhaps you know, the raid to which reference was made took place in the front line Canove di Sotto, Gordon Trench etc. The raid began at midnight on the 8th August 1918 and 2 Austrian officers and 49 men were taken prisoner together with several machine guns and stores. Later the battalion was transferred to the Western Front.
As regards the death of Captain Pritchard MC, MID who was KIA on the 23rd October 1918 in a Brigade attack towards Pommereuil, (9th Devons, 21st Manchesters & 20th Manchesters), the initial success of the action was obscure at first, but eventually the battalion entered Pommereuil. The D959 -Le Cateau to Landrecies road crosses a stream called the Richemont Stream. Whilst in summer it is of shallow depth, on the 23 October 1918 it was six feet deep and required the construction of 14 bridges to enable a crossing to be made. The 20th Manchesters provided 30 men to assist the RE in this task. (I have read somewhere that some men actually waded this stream). The arrival of the Manchesters in Pommereuil was particularly welcome to the villagers as many were ill and the services of the Medical Officers were especially welcome.
As you say, the existence of a photograph of Captain Pritchard in your relative's collection is a mystery, but it could be that Pritchard was Sgt. Whitlam's Company Commander? PhilipG.