Measurement of Sprenger/Stubben PONY size short-shanked hackamore?

(My apologies for the cross-post!)

I’m considering a pony size Sprenger or Stubben short-shanked hackamore for trail riding my mare. Does anyone here have one they could measure for me? Basically I want the circumference of the noseband and curb strap on their loosest setting.

I’ve seen the horse-sized ones in person and they are way too large for her dainty head. (The cheap ones don’t work, either. Of course.)