I was very lucky with the bolts holding the grill in. In fact, evey bolt that I have removed from this car has come easily so far. What I thought was old oil and road grime underneath, turned out to be a very thick coating of fish oil. The crossmember, suspension, inner guards and inside the boot are covered in it. You can also see where it has dribbled out of the doors and from under the sill plates. It has gone hard though, and will be a mongrel to remove if I ever decide to do a concourse restoration on it.
It appears that the reason the latch wouldn't work was that the cable inner had seized in the conduit. As simple as that. Once I got it out and I could get some WD 40 down it, it slowly came good to the point where it operates like a new one again now. Not that I am going to use it. I have left it off so I never have to spend an hour undoing the three bolts that hold the latch on ever again. There is just no room to move with the bonnet shut.
This pick shows the latch with the cable pushed all the way in and the locking pin right through the holes.
And how it was actually sitting while I was trying to open it. When I was working on it, from underneath, I could just see the end of that pin, but I had no idea at the time what it was. I assumed the bonnet cable pulled on a latch like the later Holdens.
While they were off the car, I disassembled the grill and bumper and hit them with the Purple polish.
The only bad rust on the inside of the bumpers and over riders was where the spot lights had been mounted.
Most of the bolts looked like this, with the zinc still looking like it was applied last week, not 61 years ago.
I assume it is the original radiator.