Within a month of purchasing 52F and bringing the bird home we removed the headliner and stripped out all of the original fiberglass insulation to fix a front fresh air duct that seem to be plugged up. The following is what was found...
The main carry-thru Spar had an OEM foam pad glued around it to soften the blow of passangers bumping their heads. Because of years of wicking moisture from the air, a chemical reaction occured between the moist pad and the Cessna glue. The pictures that follow shows what years of neglect and improper inspections will do to your spar. Not a pretty site but lucky for us, the spar had enough slop from the manufacuring process, according to Cessna's assessment, that it was repairable but just barely!
I looked high & low trying to find a new spar...no luck! I was told by Cessna at the time, March '04, that it would take at least 6 to 8 months to get a replacement part and the cost was not known until after the part was made! That's scary!!! At the time, finding a used, servicable spar proved to be quite impossible!
In 2011, I did find a used spar from a '68 210 but after an initial visual inspection from an Eddy Current expert inspection company...they said it was not usuable because of extensive embedded micro corrosion. This replacement project has been permanantely put on hold!