I've been practicing free motion "embroidery" using the Stoppax darner attachment which came with my Aluminium 201 and the hopper foot I bought from Roger. It needs a lot more practice to really call it embroidery and it's quite noisy as the Stoppax thingie makes the foot bounce up and down.
However, when I replaced these with the regular straight stitch foot, the needle was directly above the toe of the foot
and looking at it closely it was clear that the foot was not parallel with the edge of the throat plate, but I couldn't move/rotate it at all, even using pliars.
When I took the face plate off there was a clamp with a screw on the presser bar, just below the pressure spring. That screw was quite hard to crack, but when it did just a quarter turn was enough to allow the bar and the foot to turn. So I realigned it, tightened the screw and it's all fine,
so feeling chuffed with myself that I was able to work out what was wrong, and put it right all by myself!