Several videos showing the internal construction of the older type Wylex Standard fuseboxes.
This example is a 4 way brown fusebox with a wooden frame. Most likely from the 1970s, it is still in good condition.
Maximum of 30A per way, 60A total - perfectly adequate in 1975. However totally unsuitable for connecting to high power loads such as an electric shower, and there is no provision for adding RCDs which are required in the majority of modern installations.
The correct way to replace fusewire in a Wylex fusebox.
A similar procedure applies to rewireable fuses of other makes.
While somewhat tedious, fuse replacement should be a rare occurrence. If not, there is a problem with the installation which must be located and repaired.
Although more convenient to reset than rewireable fuses, spending money to 'upgrade' an older fusebox by installing plug in circuit breakers is rarely worthwhile, and offers little or no benefits.
The key point here is that these plug in devices do exactly the same thing as the fuses they replace - disconnect in the event of an overload or short circuit.
They do NOT offer any additional protection such as would be provided by an RCD in a modern consumer unit.