It's messy for sure, but not at all untypical for a service which has been changed around over the years.
I is the PoCo's service fuse/cut-out, and the cable snaking its way into the top is their property.
Meter A is a modern type, as is the main RCD (GFI equiv.)which it feeds at H. It's quite common to see a modern RCD added to an older system in this way. Boxes D and F coming off of this RCD are much older.
This looks as though it's in a garage, or some similar location, so I'd guess that F is probably just feeding sockets and/or lights within this building.
Meter B is feeding into timeswitch/contactor C. As Adam says, the neutral is just providing power for the timer & control circuit. The unit this feeds at E is one of the older voltage-operated ELCBs (Earth-Leakage Circuit Breakers), which relies on a solenoid coil to trip on sensing voltage on the building earth conductors relative to its reference ground rod. Note the two earth conductors running to it. Voltage ELCBs have been obsolete for over 30 years, but there are still a lot in service. The cabling from E to G has been there a while -- Note the plain green earths instead of green/yellow.
