If it was 2,750 ton dock, then it would have been one of a class of eight such docks built in WW2
AFD.12 - based Scapa Flow 1940 - 45
AFD.17 - Based Reykjavik 1942 - 44, then 1944 towed to Sydney, Australia via Aden & India
AFD.18 - at Oban, Scotland 1942-43 then towed to the Mediterranean for 1943-44 then to Hong Kong 1945
AFD,19 - West Scotland 1943- 45
AFD.20 - at Greenock 1943-44 then towed to Malta 1945
AFD,21 - at Belfast 1943-45
AFD.22 - West Scotland 1943 - 45 then to India 1945
AFD.26 - built and served in India 1942 - 45
If he was at Baldur, then the likely dock would be AFD.17 which was towed by the tugs Lariat and Eminent in late-1944 from Reykjavik to the Med for onward movement to Australia