When I have anything that requires POCO involvement I meet with their engineer on site that way I can open cabinets and transformers and not be surprised by hidden problems.
You could loose lots of future work. That will have to be a call sparky76 makes. You never know what word of mouth can do for you. You have to make the call as to whether the word is good or bad.
You never know what word of mouth can do for you or TO you!!
I just finished a rewire of an old building that had about 60 years' worth of different wiring methods in it, and chalked it up to a "learning experience", as I royally screwed myself on the pricing. But it was for a friend, and he never questioned anything we did. All came out good in the end I guess. Good luck on your project. I'm not sure if I would have expected to find something in the sealed panel or not. Most likely not. But, as inquisitive as I am, I probably would have called the POCO and asked some questions. I always try to analyze every possible scenario ahead of time, but I still get bit in the a*! once in a while!!