If you screw the jets right up you'll get no fuel at all. Screwing them down brings them down to a point on the tapered needle gives the correct ratio for tickover. You turn and a half is OK but try 12 flats to start off. The choke pulls the jet further down the taper and gives more fuel. Don't be tempted to pump the gas pedal when trying to start. This will give more air and less fuel, quite the opposite you need for starting. There is no accelerator pump on an SU.
You're getting comments about the electrics so go with those if needed. I also wondered if something got burnt or knocked off in the aftermath of the fire but not much on that side of the engine except the dynamo or alternator wiring. Worth looking around though. Check the wires on the starter motor and the tightness of the connections on the back of the ignition switch. As always, clean the fuses.
As is often said most carb problems turn out to be electrical............