Just to add to your question, it may help it may not. I am one of the end terrace of a terrace of 7. We are all on a looped supply, 1 loop comes up my side wall splits to mine then feeds 2 other properties so 3 of the 7 from the incoming loop on my wall, then the remaining 4 in the terrace are looped together on a separate incoming loop on the end of the wall of the other end terrace the other side.
Its a rubber incoming cable with 2 cores. The earthing arrangement has always been like this.
I have also attached a photo of the setup before he came in and installed the new CU
View attachment 98921
On another note regards the loop, have a look at these pictures and see how dangerous this looks to you
View attachment 98922View attachment 98923View attachment 98924View attachment 98925