In case you haven’t seen this: the 75 Squadron ORB (transcribed in Simon Somerville’s website
here) says this regarding the location of WHEELWRIGHT 67 in March 1944:
“Operation WHEELWRIGHT 67 (successful). The m/n crew in Stirling III ‘P’ took off at 20.55 hours. The target area was reached at 00.08 hours being pin pointed by the river bend and railway bridge by Tonneins where a glimpse of red lights were seen.”
Cheers, Pat