I believe they changed the following when they went from Mk I to Mk II.
1) Windows - rounded
2) Wood trim - removed
3) Went to a center post under the mast verses the two posts "bridge" design.
4) Slight change in the hull design above the waterline I think
5) Moved the electrical panel from the port side close to floor -- up ---
starboard side under deck ???
6) Seems like the newer models have vinyl covers over the interior cushions verses corduroy
7) I think the storage compartment on thestarboard side is "finished".
.
The better sailors, sail the MK I's
Hershey
427 Mk I