Hi Snider,
You are correct, the bowsprit is slightly longer in the Mark II - an extra foot I believe. Here are the specs for the Mark II, as listed in the original sales brochure:
LOA: 37'
LOD: 30'11"
WL: 25'
Beam: 10'8"
Draft: 4'5"
Displacement: 16,000lbs
Ballast (lead): 6,000lbs
Sail Area: 596 sq ft.
Headroom: 6'5"
If you need any more info you can send me a message directly. There's also a Yahoo group with a bunch of information, including the original brochures, a magazine article from the 70s and a bunch of pictures from the members.
Mariah31 : Pacific Seacraft Mariah 31
I could add that we love our boat, but I don't imagine you'd hear differently from any member here.