Right...the date listed is the date the CA took over the account and has nothing to do with SOL. SOL is a good thing. You can't be sued.
I'd dispute via each CRA and, at the same time, DV them CMRRR.
Wait until the results come back from the CRAs (30 days or so later, or less). I'd also wait a little while longer for a response for the DV. CRAs have 30 days but CAs can take their time.
If no response over the next couple months, I'd try a PFD.