Clejuso 1950 Handcuffs?

Hello All, Can anyone tell me how long or approximately how many of these were produced? The lock case is different than the later models? Does anyone know if this type of lock case was better than the later version or vice versa?

All & All a Unique Clejuso Handcuff I haven't seen many of?

http://cgi.ebay.com/1950-Clejuso-Handcu ... dZViewItem