Ah good, there is no play in it, just weeping air out the seal when compressor was pressurized. Wasn't leaking enough to hear but could see when spraying soapy water on it.
Found 7 boost leaks and 1 vacuum leak on the car so hopefully it's a completely different beast now.
Thanks for the offer but I'm quite happy with its performance and will stick with it.
Edit- and the crankcase circuit wasn't pressurized so the oil seals are fine