Hi guys… just another little update with what ive tried. There was a bit of confusion with the admin calendar event email… i hadn't realised its not treated like an email… but… if you forward the even to yourself it becomes an email… with all the booking details (time date, custom fields etc) in free text format. I was then able to create a flow and extract the booking text I needed and then use it ie in a List or forward on to anyone that needs to booking data. Maybe a bit clunky forwarding myself emails (and I had to avoid a constant loop) but has worked ok. You can either use Rules in Outlook to autoforward, or create a flow just for that aspect (or maybe it could even be combined).
While I have no apparent access to working official Booking connectors.. maybe this might help someone.