1974 450sl

I replaced the belts and accidently sparked a wrench against possibly the alternator before disconnecting the battery. When I buttoned it all up the engine cranks, fuel pump works, provides fuels from the smell, and spark plug is emitting a spark. It ran for about 2 seconds then died. Never stated up again after that.

The battery is fine. The coil seems to be fine with checking the resistance with a multimeter. The fuel pump comes on and pumps gas. I suspect it might be:
1. a blown fuse - the ones under the dash on passenger side looked fine
2. another fuse box for ignition system - not sure when it is located?
3. Engine Control Unit (ECU) module
4. Electronic Ignition System (EIS) module
5. Fuel Relay switch - no idea where this is located?

I value any feedback and help please?!