Retro Heels Frankenstein Madame Zombie FX Size 8

These are my favorite super cute retro pin-up heels that are Frankenstein-themed. They're by Madame Zombie FX and they say size 8.5 but they were too small for me; honestly I feel like they would fit a size 7.5/8 best. Because they didn't fit, I never wore them out; just tried them on. The straps look like they have large Frankenstein "stitching" across them, and the back of the heel has a cute lightning bolt cutout. These feel like they may be leather but I can't be sure.