You could always try a style L bobbin, they are suppose to be universal, at least to a degree, but they have their limits. They are the correct width for a class 66 bobbin case, but they have flat sides and can you find a version that has the right hight for a class 66 bobbin case (same as Apollo). A 15 bobbin will act up on the 401. Again, you might have to wind your own bobbins.