f Bicester was on the Government pipeline system (GPSS)
I don't believe it was. The construction is inconsistent with any housing that would have been built around a fuel manifold, as it would have required high and low ventilation. The damp-proofing would point either to an inhabited building (unlikely as there are no windows), or a housing for an electrical installation. If it was a pump-house, you would need a BFI close to it. It would have been pants as a pill-box - again no windows or loop holes and brick structures can be dismantled by a GPMG, let alone anything bigger.