It used to be possible to add an item on the Watch list to another custom list, and then remove the listing from the Watch List and keep the item on the other custom list -- but eBay seems to have recently changed how that works, and now it appears that deleting an item from the Watch List also deletes the item from any other lists at the same time.
Deleting an item from a custom lists provides an option to delete the item only from that list, or from all lists at the same time. Doing the same thing from the Watch List does not provide that option, and the deletion removes the item from all lists.
You can get around this as follows: Open each item on your Watch List that you want to move to another list (or keep on another list) in a new browser tab. Delete the item(s) from your Watch List. Go to the browser tab with the item listing, and then add the item to the custom list. You may need to refresh the page first if the item was already on the list and still appears to be on the list.
