Can you provide more (proces and requirement) context?
The carrying over you are mentioning is not fully clear for me. Where you able to add a registered product to the opportunity? Does it concern a product that the customer still needs to buy or is it a registered product that is already available in his installed base that offers a commercial opporutnity for example a full revision?
In general when you add the ticket tab in the opportunity transaction you can create a ticket with reference to the opportunity. In the quick create screen, that appears when you select in the ticket tab within the opporutnity 'new', you can select among other elements the installed base, installation point and serial number from the customers data base. This is then the scenario where you are referring to the existing installed base of the customer.