If you pull out the "MAIN LIGHTS" block on the left, check power coming out of the "MAIN RANGE" terminals at the top. If the RANGE terminals are dead, this is a 60 amp panel. If there is still power at the RANGE pull, it's a split bus 100 amp panel. Also, a 60 amp service will only have 6awg wire feeding the mains. With a 100 amp split bus panel like this, the main Lights and Range blocks are each fed individually from the main terminals. On a 60 amp panel, power to the plug fuses and the Range block all passes through the 60 amp Main Lights pull.
The way I was taught, if the label is illegible or missing on an older fuse panel of this style, is to pull the main fuse block, then check all the 240V appliances for power, typically the other fuse block will house 40 amp fuses for the range or clothes dryer. If everything is powered down it can be estimated to be a 60 amp panel. Otherwise there's a better chance of it being 100 amps, assuming it's fed from 4awg copper or 2awg aluminum, and there's a square meter base. A similar rule of thumb can be used estimate the capacity of a split buss breaker panel. Above all a home inspector should never assume a split buss fuse or breaker box is 100 amps if the label is gone. They might choose to write service ampacity unknown, or "service estimated 100 amps, recommend further evaluation by a licensed electrician or electrical contractor "
If all 4 of the plug fuses are 15 amps and it is being used with 14 gauge wire, and there are no 220 volt appliances, it is probably a 60 amp panel, but if 12 gauge wire is being used, it could 80 amps. If there is an electric stove or electric dryer, it might be as much as 100 amps.
Did anyone notice the service conductors are two different types of conductors? On right is old type, on left, newer plastic covered. Also, I hope ste range fuse holder has 15 amp fuses because it has #14 on it.
