This is one of those, could it be done.... did I need to use the built-in firebase component, or the extensions available, in order to use Firebase database and storage, and operate secure rules. Well after some research and testing, it turns out that it could be done.
Find out how:
Firebase with a Web Component
My thanks @ChrisWard for proof reading and suggestions
[EDIT - Now updated to include the new PATCH feature of the web component]