Hi Mal – thanks for your answer.
I agree with you that some albums that are easily accessible are fantastic and quite cheap too. Some of the albums that are normally around in the rare groove scene, for example, are not that rare (think Donald Byrd). It's a brilliant LP though.
Leo's Sunshipp is not rare rare (like the Mighty Ryders you mentioned); but it's a brilliant LP from start to finish IMO.
There are a few that I don't know there, so thank you.