Great pix, Nigel.
You'd have to wonder who would be fooled by the badgework on that Kapitan Station Wagon. Irrespective of whether it's an FE or FC (and I think it's actually the former) the shape of the FE was well enough known by 1957 when the wagon was released that I doubt this would have fooled too many people. Was a prototype wagon already about prior to the FE Sedan's general release? That's what I reckon this is.
It's also more likely an FE since it has no indicator/parkers, and by the time the FC was released Lang Lang was set up for secret road testing, so this sort of charade wasn't required. Finally, I can't see what benefit there would have been in road testing what is essentially just a face-lifted vehicle. No, I'm not going to start that discussion up again, even tho it is a Friday....
cheers
RET