To complete the loop, I got it opened. I think the link above is for a single latch hood. I found that a determined fellow with long arms and dexterous fingers can reach the driver's side latch mechanism from below. If the mechanism is not jammed (I thought maybe I had dropped a nut down there or something and could not figure what had made it suddenly stop working), you can just push the latch release, which you can feel on the release wire (that comes from the driver's compartment). You push it away from the center of the vehicle (on the driver's side) or (and I have not done this but I know the direction is correct) toward the center of the vehicle on the rider's side (in the US).

It turns out that I had disconnected the upper radiator hose and, when I reconnected it, I threaded the armored wire which is the hood release mechanism under the upper radiator hose when the upper radiator hose should be under the armored cable. Careless me!