The Adjutant General's Corps (AGC) is one of the largest Corps in the British Army and provides support in the form of Combat Human Resources Specialists, Military Police, Military Provost Staff, Military Provost Guard Service, Educational and Training Services and Army Legal Services.
It's like the Admin sections!
The Household Division consists of 7 Regiments:
Life Guards and Blues & Royals - which make up the Household Cavalry
Grenadier Guards, Coldstream Guards, Scots Guards, Irish Guards and Welsh Guards - which make up the Foot Guards.
The Royal Fusiliers (City of London Regiment) was an infantry regiment of the British Army until 1968 when it was amalgamated with other regiments to form the Royal Regiment of Fusiliers.
Bearing in mind the date, I reckon it's The Royal Fusiliers!
If he had been in the Household Division, surely he would have worn his Regimental Tie?