Looks to be leaking at every joint, except the brass.
Looks to me like it might be dripping from above. is there a bleed screw? Show us the top end.
There is a rust drip from the bottom silver nut
Think you have had too much brandy , like everyone said nuts need tightening ( clockwise) to tighten.What on earth are you two wittering on about? There is a rust drip from the bottom silver nut. The OP needs to hold the body of the lock shield, I use a mole wrench, then using a suitable spanner nip up the bottom silver nut by turning it anti-clockwise. Just for the OP's interest when I had a similar drip it was the olive that had become crushed due to multiple nip ups. If that is the case for yours, ie nipping up the nut doesn't stop the drip then it becomes a biggish, but more importantly, a messy job unless you drain down your system.
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