The actual cockpit floor is now in place. I wanted to get a look at how well the captain's chair would hold in place, as well as make sure the engine cowling was unaffected by the new aluminum edging, so I put the seats and cowling back into the boat for a preview.
The T-nuts seemed to work well...The pedestal was reinstalled without major incident and is solid as a rock.
IMPORTANT NOTE FOR ANYONE ELSE TRYING TO USE THEM:
Learn from my mistakes...put a piece of tape or something over your predrilled holes before you fiberglass over them..I had resin drip down through the hole and into the thread of one of my t-nuts, and had to fight with it for about 10 minutes to get a bolt through it!