denachtenmai
I had read somewhere that a F96 Camera had been installed in the oblique mode on a Hastings, whether this was used with the door off or through a clear panel fitted in the door I do not know but your clandestine version sounds much better.
Do you know what happened to TG507 after it was retired from use in 68 or 69, I know where most Hastings ended up but not 507.