1978 Cal 30 renovation

[smilingbobby]

Hi. Real new to sailing. I bought my Cal in Oct of 2011.She had been sitting on land for six years. She needs some work. I have to replace the mahogany plywood between the cabin and the cockpit. Very expensive plywood. My main concern was the engine. I got it running without much work. It's a Farymann deasel. I'm in the process of insulating one of the sectiions of the cabin. It's taking longer than I thought. I'm doing the shinney double bubble wrap and pink foam insulation. I'm not going to tackle another section now.
There is one small soft area on the ceiling of the cabin. This is where the screws attach to the hand rail. The is a 3/8 inch space under the hand rail where the deck has separated from the rail. I'm not sure what to do about it. I'm thinking of cutting a small square in the cabin ceiling to see about rot. How do I get the deck back to the hand rail. I was thinking of fiberglass reinforced body filler to fill the area between the deck fiberglass and the cabin ceiling fiberglass layer. I don't know how to raise the deck to meet the rail.: