This evening was spent making a start on the framing to box in the wheelarch and the gas fill pipe, its surprising just how long it takes to measure up, and mark out the floor and wall, and then cut glue and screw battens.
In the photograph you can clearly the gas fill point and pipe and the (un)intentional gas dropout. As you can also see I decided to box the wheelarch as a single unit but with a partition to allow me to fill the wheelarch section with insulation and still possibly use the gas fill pipe section as a gas locker.
The fitting in the gas dropout is a soffit vent that I happened to have in one of my buckets of bits, luckily it is designed to fit a 70mm diameter hole which just happens to be the size of the hole in the floor.