The Singer genuine 401, 403, 500, and 503 sewing machines utilize the Simanco 172201 straight stitch needle plate AK3, which I classified as new old stock in beautiful condition.

The Singer genuine 401, 403, 500, and 503 sewing machines utilize the Simanco 172201 straight stitch needle plate AK3, which is classified as new old stock. Acquired from a sewing company six and a half years ago, these needle plates are in excellent condition. Each plate has been thoroughly inspected, revealing no notable needle strikes. Minor abrasions may exist due to prior storage, but all plates have been individually bagged to ensure preservation.