Welcome to rootschat ganerez.

You’ve come to the right place for help, as evidenced already by what Gibel, Andy and Alan have found.
Depending on how much trouble and expense you would like to go to, you could purchase James Clark’s service record from the MOD (Ministry of Defence) but there is a cost of £30 and a wait of about a year. A death certificate for the soldier also needs to be provided, though I believe there is a version of the service record for non family members however I don’t know if that gives you the personal details (such as NOK) that you are looking for. The cost and wait time is not ideal however.
Unfortunately such a common name will make the search more difficult, and we will need to find something to identify him (age, next of kin, place of birth etc) before searching for him further in census, BMD records etc.
Ganerez, if you reply here a couple more times, the personal messaging system will be activated. This can be useful in case someone needs to contact you privately, perhaps if living relatives are found. (We are not allowed to name living people on this forum).
One last thought …. I’m not sure if it is still possible, but the medal office at Imjin Barracks used to give information about soldier’s medal entitlements. I wonder if you (or someone UK based) contacted them with his name and number, would they be able to provide information about what medals he received, when and where they were sent, and to whom they were sent? That could be James himself or family and may indicate if he survived, and would at least give you an address.
