Hello,

A previous owner has buried some SWA to take power from the house to
the garage. Whilst doing some gardening, I found a metal junction box
buried in the soil. It looks like it is coated in some sort of "lard";
I presume to keep moisture out and to prevent rusting but it looks on
its last legs.

The cable runs to the far corner of the garage; I think if I ran the
existing cable to the nearest corner, I would not need a join and I
could do away with the box.

I have found the wiki very useful to learn about swa.

I am unsu should the SWA bend through almost ninety degrees as it
enters or leaves a building? That's what the current set-up is like
but that seems quite a bend to me. Would it be better to run the swa
up to a junction box on the wall, like this:
http://www.toolstation.com/shop/p61729?table=no

and from that take some T&E inside?

Thanks,
Stephen.