Ahh...but to have a blueprint of one's soul as you asked.. Try the eyes (aye aye!)! They are the windows to the soul. I believe that the master Ted Brewer is alive and well and answers email, or so, I have been told. Good luck.
I have the set of drawings purchased from Ted Brewer, and that specific detail isn't included. Morgan handled some of the construction details, and/or changed some of the details Ted originally drew, especially on the 383/4 when there were some structural changes around the mast step. There is an IGU (Internal Glass Unit) that is detailed in the plans and supports some of the cabin sole. The IGU consists of two fiberglass tubs under the settee's that hold the water tanks, and supports the Fuel tank between them. It adds structural support and ties everything together.