Confused on fuses

[Ed McCarroll <EMCCARROLL@magnum.mco.edu>]

        Blew a fuse on the 1960 MGA.   My available reference doesn't
        show fuse ratings.   The spent fuse was a GE sfe 15a.   Two
        questions: What is the correct rating for the fuse in location 
        A 4?  (Every thing on the car is standard - no electrical extras).
         What is the difference between 15 amp. fuses with either the
        prefix SFE or AGC?   What do I buy?