We buy used transformer oil in small and large quantities.we are based in lagos but we buy from all parts of nigeria.if you know people who repair, refurbish or manufacture transformer or PHCN staff in maintainance section or private companies with dedicated transformer.Note that transformer oil is like engine oil, it require changing after certain period.when old oil is taken away and replaced with new one. It that old one that we buy.It is legit and handled by authorized professionals.pls call me if you've got any for me on 08189812914