Realtors can have stiff penalties if we intentionally lie or hide any "material facts" about the home. Although I will say that when it comes to the items you have discussed most of us take the sellers word for it on the "seller disclosure", and then simply relay this on the MLS.
It is possible that the work was completed without permits. Line 71 of the seller disclosure technically gives the seller an opportunity to let you know of this. However, in my experience most sellers have no clue if a contractor does this. The only time I see that line filled out is if the homeowner completed it themselves. During the inspection you should have a clearer idea of the "age" of these replacements.
If you are simply in the inspection period then you have done your job well and I would not be concerned about recourse, because you will probably just walk away. Although, I will reiterate that regardless of whether the seller mislead you or not if the mechanicals of the property pan out is it worth walking away? What about maybe bringing this up to the seller and asking a price reduction somewhat?
If you have already purchased the home the usual recourse is arbitration (if you and the seller agreed to it) as long as it falls within the timeline.
In the end though we are not attorneys and can not give legal advice. Any time you decide to take legal action in a real estate transaction the best route is to have them on your side.