IF it helps?
I bought a couple of lovely little LED lamps with flexible metal "swan necks" and a very strong magnetic base. Sold as sewing machine lights, but my wife's machine has little or no "steel" in it's construction (although a very good machine, it's mainly plastic and cast alloy of some sort). So I now have 2! One is perfect on my Exc 21 and the other gets moved about all over the place in the shop). VERY useful.
Sorry I can't remember who I bought them from (China direct) but they really cost only a few quid, and delivery was very quick (about 10 days if I remember).
Sorry to be so vague (it's a few years back now) but I can do a photo if you need one.