As a quick test, instead of trying to start with the spark lever up, pull it down. If the initial ignition timing has accidentally been set very retarded, this might get it back into the range where it will at least start.
Okay folks, time for an update:
1. I have timed it on #4, still won't start
2. I have put on a working carburettor from another Model A
3. I found that the points were not too good, so replaced them with new points
4. I have tried different GAV openings, to no avail
5. I have put a new condenser in
6. Yes, the plugs are wet
7. I tried some starting fluid, and got a small "humph" out of the engine, but still did not start
Hooray! The car has started! We used some more starting fluid, and it finally fired up.
But....
There is a lot of popping and backfiring, and the engine wants to race. If I try and cut the accelerator back a little, the engine wants to die.
I found that the filter in the fuel sediment bowl was badly clogged. After cleaning it up, the car started without the starting fluid, but still with the racing and popping