I would strongly suggest that you bring in a Home Inspector to check out that issue. A good home inspector will look for
-rusted, corroded, loose or broken service box
-more then 6 hand-movements to disconnect power (Always favorable to have minimal steps in an emergency)
-if there are any incompatible components
-Tapping before the main disconnect
-overheating, arcing, burned wiring
-inspect fuses and breakers for proper amperage
Fuses are not a problem when you take into consideration the load on your home. I lived in a home south of Boston (built in the early 1800s) that had a fuse box and I did not have a problem. If you decide to update appliances (washer/dryer, stove, fridge, etc) then you'll have to consider the electrical load you are applying, and you will have to update the ampere capacity. A Home Inspector can give you a fairly good estimate of the load placed on your house currently and if it is sufficient enough. That is also something an educated buyer should be aware of as well with his home inspector.