finally got round to sorting this out. the new gasket leaked pretty much instantly as soon as the car was run. took it off and could clearly see where the oil was making its way through. it was seeping through where the cam caps meet the sealing face.
cleaned the gasket up, applied a little gasket sealant in those areas and refitted, all fine so far.
as for compression; i got around 235psi+- 10psi across all 4 cylinders, so that is fine.