I've just bought a RHS headlight from GSF and was all ready to fit it when I noticed it didn't look quite right. The photo shows my original Lucas on the left and the new Denji one on the right.
You'll see the two main problems are the sidelight is on the opposite side of the body, and the ball-joint clip is round the wrong way (socket in the Lucas one faces away from you, whereas the Denji socket faces towards you).
There's no way this going to fit in the car, so it'll need to be sent back. Anyone else experienced this from GSF and had any luck getting a suitable replacement?