Okay, well in that case, if are quite sure you know what you saw, I would go with David's suggestion, if he was a member of their 3rd Battalion, he would have been a Militiaman, if David has already looked at the available online folio in WO96, the only thing left to do would be a manual search in the same to establish if his papers have survived, I would think not, but, that is the only way to be sure.
Militia battalions were embodied for service as soon as the war began, normally, to replace Army battalions who had left for service in South Africa or to replace those on garrison duties in other parts of the country and indeed the empire, so you often find that they moved out of their own regimental districts here in Great Britain, so the next thing to do would be to look at that particular battalions history in detail.
