BoxRec

Given that this fight took place at a time when Liston was considered the number one contender and Folley just behind I'm surprised I've never known of the fight to have been televised.
Liston's next fight with Machen was covered in full and is still readily available as is his fight with Westphal and Harris. The Folley fight took place in Denver which might have been a factor given that it wasn't a fight 'hub' at that time like New York or Chicago.
Has anybody seen the fight ?

To be honest I don't know. I remember seeing something several years ago (Maybe on Classic Sports Network) but that may have only been highlights. I checked Youtube, and there are a lot of Folley fights, a lot of Liston fights, but their fight doesn't seem to be up there.

The fight was not televised. It was scheduled to be shown on closed circuit in theaters as a double header with Archie Moore-Erich Shoeppner but Moore dropped out of the Schoeppner fight and the closed circuit company didnt think Liston-Folley was a big enough draw to headline so the cancelled the whole thing.

So was it even filmed?

It's always been one of those impossible to find fights.