Niagara 35 need help

[robfuse]

Dear Niagara 35 owners, I'm getting close to choice my next boat. One of them is 1981 Niagara 35. Boat is very clean and well maintained. Surveyed in July 2017. Surveyor find few areas of concern. What do you think about it?
1. Hull low humidity
2. Rudder-A vacuum about 3' round on the port side of the lower part. Recommended epoxy injection-?
3.Bridge-low humidity on the part of the bridge . Medium/raise the starboard side of the hatch, between the butt and the chain plate to starboard, on the lower stanchion and the genoa rail.
A place with delamination observed or an old repair was made on starboard hatch and some small voids on the forward pass.
4. Deck-House- humidity low.Three empty about 3-4' round observed on the deckhouse.( no recommendation- monitoring suggested.
Besides everything looks good ( few fixable things) Overall condition-Average.
This is freshwater boat.
I appreciate any insights. Thank you all.
Robert

[Bleemus]

Make sure to take a real hard look at the mast step. It is glass with a wood core. If the drain at the bottom of the mast is blocked it can cause seepage around the bolts into the wooden core causing it to rot.

[AiniA]

I opened the rudder on my N35 to replace the steel bits. The shaft is stainless but the horizontal bits are carbon steel and were corroded. I had rusty water coming out the top of the rudder around the shaft in the winter when the water in the rudder froze. I took the rudder off the boat and cut the rudder apart with a handsaw. Took out the shaft and web and had the carbon parts replaced with stainless. Also removed any of the foam that was not perfect. Put the steel bits back (left enough foam to act as a support for the steel. Seal the edges will f/g tape and filled the void with West epoxy with quite a bit of filler in it. Put this in very slowly as it generates a lot of heat. Put a layer of rubber good around the shaft - this probably should be done every few years since this is wear the water gets in. It really was not that hard a job - just took care.