Ian, I was in that forest some years back when Moira had us all out trying to find woodcock for the BTO and it is spooky! I took my spaniel Skye as back-up but by the time dusk had fallen she was barking at every tuft of grass in the path and shivering with fright when we sat down to wait for the 'roding' to begin. It didn't but I did hear a nightjar in an area that had only just been cut!
The following year karen Gregory did that area for the nightjar survey(Skye told Moira we'd do a different patch)and the nightjar performed for her. I'm glad you've heard it as it confirms breeding in SN75 and saves me a job!
As a swop I'll tell you that this morning near Pont Llanio (SN 65) I watched a willow tit feeding young in a rotten stump just above a willow warbler doing the same. There was a swan with 5 young and 1 young moorhen also.