Vintage 70s Silver Disco Platform Heels Sandals Shoes Open Toe 5 B
Size 5 B but should fit 5. 5 too - I wear 6 narrow & these are just a bit snug to wear comfortably, I put through last hole on strap and pinky toe was tight. Compare measurements to a similar shoe that fits you well:
8 3/4" long from inside toe to inside heel. 2" across inner heel. 2 1/2" across at ball of foot, inside. 2 3/4" heel.
Please see photos (use zoom feature) for amount of wear to shoes.

This item is sold from an excellent, highly rated vintage boutique.