My rigger told me that Navtec recommends that the ends be re headed every ten years. I had it done because I had no idea if it has ever been done. Sounds like you have a very solid boat!
J is right. The floor there is over 2 inches thick there as I have bored through it and installed an alternate SS tube on feet for additional electronics wires which would not fit into my SS pedestal gaurd for the Radar, Autopilot, and Chartplotter. Maybe there is a leak on the bolts, or the seal under the pedestal,The floor around the pedestal is very thick. I hope you don't have a major repair. You should be able to see the pedestal bolts and the cutout for the cables from below.
I love my 35/3. I second Chef's recommendation that you join the c&c group. They know these boats inside and out - literally.