On a 1975 MGB what size fuses does it take in the fuse box top to bottom. Please Help

17/35 amp. You do not want a straight 35 amp
A straight 35 amp will not provide enough protection
1 1/8 inches long
longer ones won't fit into the various fuse holders
There are two holes in the cover for the fuse box for spares.
Reference: British Victoria Catalog Fall 2004 p.167