Yup, elevons - like the Vulcan. Concorde's droop in the down position when there is no power on the aeroplane. So that's how they'll all be for ever and ever now
When she went supersonic, there was a big movement in the wing's centre of pressure. To counteract this, fuel was indeed pumped forwards or backwards to move the CG. To have done it using trim tabs would have generated an unaccetable level of drag.
SSD