Hi neighbor,welcome to to GW and hope you don't make yourself a stranger after resolving this issue. More important,for the benifit of others with similar questions about foundation repair,let us know the outcome.
Your soil is known for causing foundation problems so it's not unusual to see the information when buying a home(it's the law the info be included). IMO,it's important that the work carries a life time warranty that is transferable to you. Read the warranty closly to be certain it doesn't have clauses that let's contractor out of it is a problem arises later on. EXTREMLY IMPORTANT that you fimilarize yourself with how to properly maintain grade and moisture near the foundation from now on. Check with everyone you can think of regarding the company that did the repair. DFW has many because of demand,some better than others. Your agent should have a brocure/paket prepared by the DFW Board Of Realtors spicifly addressing your area's soil and the effects on homes. If that report is from 19 months ago,I would want to know if it was preformed for present owner? If so,was that when house went on the market? If the house has been on he market 19+ months,that is highly irregular for Texas in general and Plano esp. Best of luck with your new home.