Compare cell contents in different columns, then fill neighbouring cells

Hello,

I'm sure this is an easy problem to solve - I just can't work out ANY (let alone a simple) solution.

I have two sheets:
- sheet 1 ('current')
- sheet 2 ('31May')

The data in column C is the same, although sorted differently and can't be re-sorted to be the same. Where the data in column C is the same in both sheets, I want to fill columns A and B into sheet 1. Please see the example attached (which is probably more clear than that description ).

Any help would be greatly appreciated!!