That's better, yes I'd say 2 way too but simply to allow large lorries(?) maybe to reverse into that yard?

Looks like a historic thing, yard was there before the one way street.

The road does seem to have all the required signage from the top of the hill, past Stranfield Close and into the bend at the bottom. The white line markings (double strip of broken 'Give Way' lines don't appear to be correct or required.

There should be some white line markings near the 'No Entry' / 'Two Way Traffic' signs just up the street to guide traffic back into the left as the one way system finishes there.

So in answer to the OP's question, the signs.