Hi Shaun/ 198 Battery or company 68 Regiment Royal Artillery. Army Number. Bombardier Rank of Corporal in RA. Photos maybe on many sites, Google 68 Field Reg RA on Google images see what turns up. You don't state which medal it is. To really know his service record, get them from here. Get a copy of military service records - GOV.UK Cost £30 and a few weeks wait but well worth it. Meanwhile put as much information on here as you can. It's surprising what might come up.
Not an RA expert but I think 198 Field Battery 68 Field Regiment, Royal Artillery British Army units from 1945 on - 68th to 75th Regiments RA 14737843 probably his army number, which indicates that he enlisted in the General Service Corps Edit. Information also here British Artillery Regiments
According to this 198 Battery wasn't in 68 Fd Regt. RA 1939-45 68 Fld Rgt Batteries 3 Sep 39 269 (Warwick), 271 (Warwick) Mar 43. 269, 271, 447 Did you just apply for his medals? Did you apply for his service records?
Shaun, if you are referring to the last link in my post #3, there is a section on ‘Field Regiments RA’ under which you will find ‘68 (South Midland) Fd Regt’ and their areas of operations.
To obtain the War Medal your Grandfather was probably serving in Burma with the 18th Field Regt RA until this regt was converted into the 68th Field Regt in 1946/7 with a 198 Bty on establishment in India. Rob