I have:
One (1) "Classics" (1/12 scale Breyer) Black leather halter, with a silver buckle and round and square wire rings as harware. It fits my arabian mare Classic horse, and my "Spirit" on the Andalusian stallion mold. It doesn't fit the Andalusian Mare mold: her mane was in the way. I made the noseband a bit bigger than Sirit's nose to allow for bigger model noses.
$5.99 for this halter, not including shipping.

Also, I can custom make a Classics (1/12 Scale) and Traditional (1/9 Scale) rope halter with a matching braided lead rope. I use embroidery floss for the correct diameter. Picture is of a Traditional halter. I only have a few colors (Forest green, light grass green, lilac, sky blue, and tan)
$5.99 for a Traditional size halter and lead in available colors, $3.99 for a Classics size halter and lead in available colors. $0.50 more for either Traditional or Classics halters in another color that I don't have.

I also have one (1) Stablemates (1/32 Scale) black western one-ear bridle that fits Breyer Dude Ranch Appaloosa, Paso Fino Mare, Red Stable Set Appy Mule, Running Thouroughbred Mold, G3 Rearing Andalusian, G3 Friesian, G3 Standing Stock Horse, G3 Standing Thouroughbred. 3.99 for this Bridle, including a small bit of "Sticky Wax", which is essential for the bit pieces to stick to the sides of the horse's mouth. (Bit pieces are pieces of wire I shaped myself.

Thank you for looking, I hope the pics come through!