Just seen your first photo, no you cant bury that like that, He should have simply used a 3/4" iron cap. You could Denzo tape it over but personally you would be best served by repiping the boiler from the meter and doing away with the barrel. One other point your earth bonding on your gas meter is as much use as chocolate fireguard, It had been attached to the lead strap and not the iron carcass. Lead as we should all know is not conductive, it was used in the old days to insulate electric cables.
Sorry take back the Denzo Ive just realised that there are compresion joints involved so No they have to be accessible at all time for gas.