I have a brand new locking, black, metal storage chest that mounts on the wheel well. It is made by Mobile Storage Systems in the UK. The model is the Micro Storage Chest. I bought this but decided to get the larger one so this micro is up for sale never installed. I have all mounting hardware and the key for the lock. These are well built and fit the Defender wheel wells perfectly. Due to size and weight a local pick up would be ideal but given enough time I can ship it domestically at buyer's expense. Brand new these run $324 USD plus shipping which is like $75. I will eat the shipping I had to pay from the UK but I am hoping to get back most of my money on the locker. I am asking $300 OBO.

More info here Micro Storage Chest - MSS-MICRO