1975 Reinell 27 cabin sole replacement

I'm currently replacing the rotted plywood cabin sole in the main salon area.Upon removal of the old flooring which was glassed in on top but unsealed underneath, I noticed the floor stringer supports were not attached to the hull, only in the area of the keel bolt inspection hatch. I guess my questions are. Is this common construction practice? Is there a structural reason for not attaching the stringers to the hull? Would I be wrong to glass in new flooring supports including the area previously not attached? Sorry one more question. Does anyone have any info, specs,original layout, or any link to a resourse for information on my boat? 1975 Reinell 27 Cheetah. Ive owned the boat for 7 years and mostly day sailed the Puget sound but I would like to refit the vessel for more serious long term sailing. the original inboard and tanks had been removed before I bought the boat. Anythig would be a great help . Thanks