fe50 - thanks for the warm welcome! That link certainly pointed me in the right direction.
If anyone else is wondering about this model, for future reference, here's what I'm using in place of "shoot":
press "shoot_half"
sleep 500
press "shoot_full"
sleep 100
release "shoot_full"
release "shoot_half"
The first sleep seems to be needed to allow the camera to focus. It'll just skip the shot if you try to shoot_full too fast.
Not sure why the second sleep is required, but lack of seemed to miss a number of shots.
Again, thanks to fe50.