My late brother was in the Royal Artillery (25 pounders) and fought in Tunisia, Sicily and Italy, mainly as a member of 17th Field Regiment within 78th Division. I have a detailed memoir of his experiences which tells me that he left northern Italy on May 10, 1945 and entered Austria, remaining there, in various specified locations, until the beginning of July 1945. At that point the Regiment was detached from the 78th and he spent several months in Milan. At the beginning of 1946 his unit reverted to the 78th which, he says "had stayed on in Carinthia throughout the preceding six or eight months based in and around Klagenfurt".
The official history may well be more specific about location but I thought I would mention it, just in case!
Chris