This link will take you to the National Archives website page for your man's medal card - you can then decide whether to pay them £2.00 to see the details:
http://www.nationalarchives.gov.uk/documentsonline/details-result.asp?Edoc_Id=3209295&queryType=1&resultcount=1The details should include his medal entitlement - date of entry in to France [or whichever theatre of war in which he served] his entitlement to the SWB - it might include more, but I wouldn't bank on it.
Given his low number and the early entry into the war he was almost certainly either a regular soldier before the war or had been one previously and was still on the reserve and so called up on 4th August or he was in the Territorials. As has already been suggested your best bet for finding out more is to see whether his service papers and/or pension records survived - if they did then they will now be available either via Ancestry [for which you will have to pay] or by actually visiting the NA at Kew, where you can search for free.
Once you have his date of entry to the War theatre then it's probably worth looking at this site:
http://www.1914-1918.net/ and see if you can see which Battalion of the Lancashire Fusiliers seems to fit his date of entry.
jds1949
