 Complete the following phrase:  As such, it was not until April 1941 that the regiment received a supply of vehicles and its first artillery pieces. These came in the form of a mix of antiquated 18-pounders and 4.5-inch howitzers. These were replaced in July with twenty-four 25-pounders when the regiment moved to Mersa Matruh, which it employed against German and Italian forces in defence of the garrison at 