The SCV product has been around since the mid seventies. The holder (frame portion) is exactly the same today as it was then. This current closer is the only valid model. The other models will need to have the arm, cover, and closer body replaced. Templating will be different. The current closer and the last model pictured at the bottom of this page are very similar. The difference is the broach on the arm. If the broach is on a diamond, then the closer is current vintage. If it is on a square, you will need to replace the closer, cover, and arm.
Detectored models and parts are no longer available.
The closers have gone through many generations. They are: