With respect to the gas meter, your local power company has the rules that they require the meter installation to comply with.
If the old service disconnect was inside the occupancy, and now is to be at the exterior meter location, then the old service entrance conductors become feeder conductors, and the grounding electrode conductor must run all the way to the exterior service disconnect.
The one grounded service entrance conductor becomes two, a separate grounded feeder conductor and a feeder equipment grounding conductor.
The old main bonding jumper must be removed from the old panel, the neutral floated and all the equipment grounding conductors moved to their own terminal bar.
