The 35-Mk 2 and 35-Mk 3 are different hulls from different decades. Both nice sailing boats, but the wind across the deck is about all they have in common. Many folks just call the Mk 2 an "Ericson 35", overlooking the first Ericson 35 from the 60's, different boat again.
The later Mk 3 has quite a bit more interior, FWIW.
Loren