I lived in Japan in a small town called Minami-Rinkan. The Minami-Rinkan Station is a railway station on the Odakyu Enoshima Line in the city of Yamato, Kanagawa, Japan. I was stationed at the Naval Air Station at Atsugi, Japan. I flew as a Naval Flight Officer in the EA-3B in Fleet Air Reconnaissance Squadron One (VQ-1)
The house was old. The fuses were not screw-in fuses, but rather a short piece of s-shaped soft metal that would melt and break the circuit if it overheated. The wiring was old!
The house did not like my washer, dryer, and window air conditioner. I simply added bigger s-fuses that could draw more current before they melted. Yes, it was dangerous. You did not run the washer, dryer or air conditioner when away from the house. The wire in the walls would warm the walls.
Read this online article. You decide if an old Screw-In fuse electrical panel is dangerous. When I rented in Japan, I abused the electrical panel by using fuses that were too much for the wiring. The electrical panel box was probably safe when used properly. I was unsafe.
Personally … when performing a loss control inspection, I would suggest circuit breakers to replace screw-in fuses. Take lots of detailed and sharp photos of the electrical panels for your report. At the end of the day, the insurance underwriter will make the final decision of what needs to be done.