Thanks to QJNeo for original design.
These grooves fits perfectly with a E14 bulb and it gives good contact with both wires.

• Adjusted the mounting so its nice and flat, with two pre-made holes (Ø 2.5mm) 20mm apart.
  (needed it for an old sewing machine where the old fixture was non-usable)

Hopefully someone else has some use for this as well :)