Who was at Tobruk April-Oct 1941

Hi this is my first post and. I am researching my Grandad, he was in 27 London Electrical Engineers searchlight regiment , that changed over to RA. I know he arrived in Egypt Dec1940 and in April 1940 2 troops of 306 Battery were sent to Tobruk and I believe he was in the harbour area, he remained there until ? He was a driver / mechanic anyone who could add to my knowledge would be greatly appreciated
Regards
Darren