Originally Posted by
chevvron
That could be it but normally the indicator for a RHC was horizontal in the signals square, especially in the 50s/60s
The convention was 'When in the ATZ, all turns are to made to the left' for which there was no signal but there should have been a signal in the signals square showing a right angled board covered in white and red stripes which would indicate 'RH circuit in force'.
Could the photos above be Pendeford by any chance?
Yes, the photos are Pendeford, taken respectively on a LH circuit day and a RH one. I can't find any photos that show the signals square.