Becki.
You really need to apply for his Service Record from the Army Personnel Centre in Glasgow. This will show which units he served in and the dates.
Go to http://www.gov.uk and, in the Search box type ‘Get a copy of military service records’.
When you have that Service Record, get in touch with me through http://www.cassinobattlefields.co.uk and I will happily decipher it for you.
Regards
Frank