Closer scrutiny of the scan would suggest that the bonnet catches are the regular J2 ones and the odd looking apron hold down knob is actually a mark on the photo.
Rob,
It seems to have been a fairly common practice (with the J2 at least) to set the windscreen back at a bit of an angle. I've seen quite a few photos of cars like that, but usually only J2s for some reason.
Car is listed in the 1982 Register as belonging to a J Eio and car had P-type engine and brakes. 1986 Register lists it as belonging to John Eio, P-type engine and 12" brakes.