M_Boats: Cabin roof

While lying on the vberth looking through the opening yesterday that used to have a cabin window in it I started wondering what it would take by way of a cross beam to carry the compression load of the mast so as to be able to remove the cabin post and open up the v berth ala the Sage. I am well able to fabricate something to fit but don't know it the cabin sides, about an inch thick since the chain plates are there in line with the mast step, and the adjacent deck structure would stand the strain. Since I have the boat pretty well torn up at present now would be a good time for such an alteration. Thoughts? fair winds, Tom B M 17 #258, 1978