If you are looking for "issues" related to this, that's better left to an experienced inspector who has done historical homes before.
If this property is truly of interest to your buyer and they want to confirm the electric, the next statement should be "put it in the offer". I would then have them hire an inspector to go through the home. This will remove the liability off of you, save you time, get the process moving forward and help your clients get what they want.
You have received some good advice, but I would not leave it up to the homeowner to give you the amperage. They will most likely add up the number on the fuses themselves and this is not indicative of the actual amperage. Many times people will substitute say a 15 amp fuse with a 25 in order to stop blowing fuses. They will fit and they will work, but this is what causes fires. Fuses are meant to blow when the circuit is overloaded. Here in Milwaukee we lose many homes every year to electrical fires.
Don't mess with trying to determine this on your own. If the sellers refuse or cannot afford to pay, it would be well worth you paying the $75-100 service call for a qualified electrician to give you the answers you are seeking.
Best of luck.
Any home built before the 1940's, may have knob and tube. Sometimes, the wiring has been updated, up to the point where it enters a wall. Then it uses the older knob and tube up through the walls.
In other situations, the wiring may have been totally replaced. Since it is in the walls, no one may know whether it is new wiring or old wiring.
The knob and tube question is totally independent on whether or not the home has fuses or circuit breakers.
Knob and tube involves the wiring throughout the house and the "fuse box" controls how much electricity goes through each wire. Whether fuses or circuit breakers, a home inspector should verify that the electricity being supplied to each wire matches what it is rated for in the distribution panel (whether fuses or circuit breakers).
A fuse box is typically tagged as needing replacement because it can't supply the electricty that is needed for most of the needs of today's home owner. Most fuse boxes are 60 amps. Today's home buyers usually want/need 100-200 amps.
A qualified electrician should be consulted.
Long & Foster Real Estate, Inc.
Lehigh Valley, PA
Lenders in our area have not stopped lending for homes containing fuses, they will often have a problem with homes with lower amperage however. If the home has a 100 amp main or larger you probably won't have a problem. Knob and Tube is a different story, however if the wiring is certified as being in good condition from a licensed electrician many lenders will approve.