Trying to find information on British Regiments in the Antwerp region in February and March 1945

Hi,

My late father fought in the Battle of Belgium in 1940 and in 1945 he served with the Belgian 3rd Battalion of Fuseliers. This Belgian unit was trained in the Antwerp region by British Officers and by the end of March 1945 they accompanied the 2nd Army into Germany. After May 8th he was in Northern Ireland and at Bisley in the U.K. with the Belgian 6th Infantry Brigade.

I would like to find out which British regiments were in the Antwerp region in February-March 1945.
Sadly up till now I have only the name of a British Lieutenant 'Bill Edgar' or 'Edgar Bill' and a photograph presumably taken at Bisley Camp. The British Officer in the general service cap appears to wear the cap badge of the Rifle Brigade.
Could anyone try to identify the cap badge of the Officer on the right ? (attached is a sharpened image) or maybe give some clues as to where I could find the information I am looking for. View attachment 25576

View attachment 25576