Complex sentence: The most famous stamp of the "large Hermes head" collection is a variety of this issue: this is the 40 lepta of the same shade as the "control numbers" of the typical stamp of this same value.
Split into simpler sentences: The most famous stamp of the "large Hermes head" collection is a variety of this issue. This is the 40 lepta of the same shade as the "control numbers" of the typical stamp of this same value.