Thank you! I think the Pfaff bobbins might fit. Converting English to metric, the Pfaff are approx. 21.43 mm diameter and 8.73 mm high. The diameter is perfect. The height could be a rounding error, but it's only .52 mm smaller. We Americans are in the dark ages in terms of our units. I've been in "unit conversion hell" my whole life, and it doesn't look like it's going to change any time soon.
And your wizardry is pretty amazing.