My house's service entrance uses a fused service equipment panel
[Linked Image from pw2.netcom.com]
Closeup of the stickers:
[Linked Image from pw2.netcom.com]

It was installed in the early 1950's. When 100A was a big service. Spares sitting behind the meter, but never had to use them.
"Aug 9 '76 failure" was a big blackout in my town... smile