To answer your question, after you create the listing and specify a shipping service and price for the UK, as you go to the next page within the listing draft, you will see a summary of your listing, as well as your fees; and on this page, you will have the ability to add Site Visibility if you so desire, which will allow members in other sites to view your item, so long as they are offered a shipping service to their country or region of the world. I am happy that you desire more members to see your item; and I am confident that this information is helpful for you. If you have any questions or concerns about this or anything else, please let us know and we'll be happy to help you further.
喜んで対応させて頂きます。