Firm called Ecolux sells them in various configurations - from the old Singer Featherweight to large throat machines.
They can be pricey, but do have a separate connector. You can buy just the lights and switch the power source from machine to machine. Fairly sturdy. I have some for both the Pfaff and the PQ1500. I sold one of my Pfaffs and left the lighting strip on. Lady that bought the machine ordered just the power supply and is delighted.