- I have for sale one (1), Used, original Hurd door lock cylinder. It is in nice shape and the cover is tight... This lock cylinder will also fit the ’39, ’40, '41, and '42 Mercury if the length is right for your application . It comes with two replacement keys. The length from where the cylinder fits against the door to the end of the shaft is 2 13/16 inches and the shaft itself is 1 11/16ths inches long….. Look at the pictures and make sure this will work for your application. The lock body diameter is the same for all models. Shipping is $5.00 Payment would have to be by PayPal or Postal Money Order Thanks, Tic