From my thinking, the fusible link would be the safety on that circuit if you removed any additional fuses/breakers. Not ideal, but there would still be something there to prevent serious damage if you had a short.
I'll have to look at my panel, I'm pretty sure the breakers on the fuse panel were standard at least starting around '85 when GM changed the fuse panel layout for more circuits. The breakers are easily replaced with standard blade fuses, so I don't think it would be unusual to find that breakers had been removed and replaced with fuses.
