I'm rewiring my new (old) house...

Is there a maximum - permissible length for meter tails?
And, being as the "existing" earthing connection to the meter bus (from the
incoming mains) is taken from the metal reinforcement sheathing -

(which in the past had NEVER been connected into the house circuit AAAGH!)

I digress, - does this indicate that it's a TN-C-S setup?
I can't see/find an earth rod, or other connection?

" To HELL with the O.D.P.M " !

Thanks in advance.