Rather open ended comment, and I am not trying to be critical here, but honestly just how many have you done in your shop?

I would be leery of any boat that has sat outside uncovered, meaning, no cockpit or full cover, under a roof. Too many of these older boats have developed leaks around hatches and other areas. They can trap water in places where it cannot get out or is not pumped out and will begin to seep in tiny voids. Boats with water standing in the bilge is a bad sign also. JMHO

7. 27s, 29s and one 35.
I'm not talking "moist" transoms that we talked people into replacing or something like that. Im talking transoms that had vanished. Full of pure mud. I have some videos on an old phone Ill post.
It's certainly not 100% guaranteed that all fountain's with that exhaust are toast, but it is 100% that they're at risk and have been compromised. Once the wood is wet, it's only a matter of time. If the boat has been in the water, the wood is wet. Fountain did not seal them. At all.

The type of wood that is used makes a big difference. There are many good boat's out there that have been running with moist wood for years, even decades.

Did a complete refresh on both motors couple years ago and the pipes were sealed by the factory. The cuts were sealed, the pipes and trim rings were sealed as well. One exhaust tip was disturbed on reinstall so I took all four out, to check then put them all back sealed again. They were well sealed, it some effort to pop them loose and remove them. Not saying all are free of the issue, any more than it would be fair to say all Fastec grids have failed Plexus bonds or hull to deck plexus failure. Maybe I'm just a lucky one.

That's fantastic! I'm sure at somepoint somebody stepped in on the rigging department and straightened it all out. It sounds like it was before your boat was built.
The years for the ones we did range from 1999-2004.

Did a survey on the Formula 357SR1 I'm looking at over the weekend. Hull was dry. Port motor needs the valves adjusted. The fuel lines are too small for the 540's and need replacing. Doing the Fountain survey Weds. Trying to get the price down on the Formula and hope to do a deal today.

I was interested in a 2007 Formula 370 SS this spring. One of the drives had been pulled because of salt water corrasion around the transom assembly. I have photos showing separation of the transom. I talked with a marine shop about a new transom. He said they run around $7000 for a formula. When I said it was a 370 SS he said and I quote, I have done enough off those and they are easy so $6500. That was a shop at the Lake of the Ozarks. For what it is worth the word (unsubstantiated comments) around the lake is the weak link on Fountains is usually wet transoms. Also Baja definitely get a majority of their transoms/stringers replaced.

Surveys are worth the cost!

Now I'm getting nervous about my 05 29 Fever that was built in 04. Need to add that to the BOAT list!

The worse thing a boat builder can do is a bad job of encapsulating wood.