In my m=github account there is an extra add-on for importing the fields assosiated with the pre-order extension. The pre-order plugin can be found here.
Easily setup pre-orders in your store so customers can order products before they are available. You can automatically or manually release and fill the orders when you’re ready and let the extension handle the rest! The pre-order experience is fully customizable and supports both pre-orders charged upfront and pre-orders charged upon release. If you’re using a supported payment gateway, pre-orders can be automatically charged upon release without the customer needing to return and pay for their order.
You can find the add-on to import it in my github account among other great free add-ons.