I generally use oneverybootleg.nl as a database for a view or comment on live recordings. It is pretty much comprehensive, however there do seem to be a lot of alternative sources or recordings of audience based recordings cropping up on trackers these days.
As for a list of what isn't shared, well I will guess we will never know until each recording becomes available. I'm sure that in the vaults there must be a number of soundboard live recordings, like the whole of Paris 83 from the MFN comp, and the master reel of the Mandela show along side a lot of obscurities. Who knows; indeed we may never know.