Is this panel 100 amp or 200 amp service and are these double taps allowed ?
120/240 volts, 100 amps.
No those double taps are not permitted unless those binding screws are listed for two conductors. I would also look closely at the wire size on the 30 amp OCPD.
Its a 100 amp service ,
No double taps are not permitted on this panel also white is being used as a hot it should be identified ( black tape or black marker )
Looks like 30 amp fuses if the wire is #12 it is over fused
This is an old service I would recommended it be checked by an Electrician immediately