Thanks for the feedback folks,
I don't mean to take away from the cruck discussion.

I can now see how this non-structural ridge made layout and assembly an easier task, but I'm still wondering:

These old time carpenters MUST have known that placing a post under these ridges would re-direct roof loads away from the plates, so why did they still not use them? As Tim suggested, was it because too large of a timber would be required for the ridge? But it seems to me, that issue was not often a limiting factor in the design of old frames. Or was it?

Tim, your earlier comment about the dropped tie as it relates to roof thrust raised yet another question. I always thought that dropping the tie from its ideal triangular arrangement resulted in an increase of rafter thrust at the plates (relative to how low it was placed) and created the need for tension joinery at tie/post, in effect doing the opposite as you suggested. Or did I misinterpret your explanation? Or am I simply a knucklehead and missing something here?

Gabel, Interesting stuff. Any particular reason why this type of ridge was not used once SR came on the scene?