The bobbin is regular size but has a huge hole in the middle.

In posts 17 & 18, I gave the part# for the bobbins ...& where you can buy them.

I have one just like it from my Mother-in-law. I call it the Monster locomotive

I just "inherited" one of of these. It's in a desk-like cabinet which is probably from an older machine. Going over websites, on man calls it a "stream liner: because it looks like an Art Deco locomotive. Yours looks much cleaner than mine! It even feels oily, and odd sensaton with the Godzilla skin!

Totally retro and beyond weird. Love it.