Rib replacement/Piper SB 1161 update

I was just down in Stockton at the Mooney facility there. They showed
me a rear spar that looked a lot like your rib. Total repair cost was
$40,000 (just to replace the spar). The spar is visible in the rear of
the wheel well. The service center is saying that the problem was
either introduced or not correctly caught by the paint facility that
repainted the Mooney 1 year earlier. Not sure if the same may apply to
you.

Pix of the Mooney spar
http://www.topgunaviation.net/topgunaviation/id7.html
The damage was noticed when the rivet heads started popping off the
spar as the corrosion expanded the Aluminum.
-Robert