I am traveling at the moment so I can't take a better pic. But maybe there is a way to save your work...
FWIW the black that you see around the cream bobbins is a spacer that I made. I did it with a router to round the corners, but that might be overkill if your pups are a more normal shape. You could do this with an exacto knife or box cutter and maybe a dremmel or sandpaper to clean up anything that needs it.
I made the spacers from hotel card keys that I spray painted black. The material is strong and thin, and the cards are just a bit larger than a pup ring, so relatively easy to cut down.
One day I will catalog the uses I make of these little cards. Remarkably useful