I can confirm that Corgi/Bassett Lowke Ace trains, Darsaed etc will run happily on Peco 0 gauge bullhead rail, some extra clearance is required on point check rails, but everything else is fine.
As an aside, the Bassett lowke is often referred to as "0 gauge standard" whose wheel standards are sort of halfway between finescale and coarse (ie Lionel)