Replacement fuse block with connections to main harness. Fuse block is of good quality. But, it is not original and the mounting holes do not align. It will fit nicely in the available space and you should be able to secure it in place using one of the two original mounting holes.
Harvey Johnson used the original lower mounting hole on his Mille GT. Then, he used a short piece of aluminum flat stock to mount the fuse block diagonally to the original upper mounting hole as shown in the photos below.