gambrel roof without perlin

hello everyone, I am hoping for some information/ opinions about a house I was in a little while ago that was built in the late 1600's. it is a cape with a gambrel roof but it did not have purlin posts and beam supporting the intersection of the two roof pitches, I haven't seen a gambrel done that way. Also the top roof pitch was probably only a 3-4pitch, which I would think a house of that era would have had a much steeper top pitch even being a gambrel. As you would expect the top plate in the front of the house is bulging out and 2nd floor joists separating, but the owner is sure that it is from the failing foundation and not the roof. The low corner on first floor seemed convincing as the culprit, until I saw the roof framing. To add to this, there is a monster beam (17"wide chestnut!) in the center of the house running in the same direction as the ridge, not perpendicular to catch 2nd floor joists that only span 9-10' . Is it possible that this house was originally a gable roof that was later converted to a gambrel? I really don't know when gambrel roofs came about in new england. Did they start out with out purlins? I would think that load transfer would have been obvious to the timber framers of those days. I wish I had a camera with me that day and could have taken pics to show but I didn't know that day I was going to end up in that house, just a chance encounter.

Well I really do think it was converted to a gambrel , and that is why no purlin posts and beams. I just dont know enough about the history of gambrel roofs to say definitely that is what happened. I was hoping someone on this site had seen this before, or knew more about the origins of the gambrel roofs and could have educated me on the subject.

Since I have never lived in New England nor have worked on old colonial NE frames, I can only guess and likely incorrectly about a building that is not well described. Please provide a description of the roof frame, members and frequency, the bracing, the connectors, ie nail type or pegs. A precise description of nails could date the frame, as would the size and conversion method of the wood framing members.