Looking for Delta 88 1973 convertible
 

We owned a 1973 Delta 88 Royale Convertible in the past. Blue with white top/interior. It was my husband's pride and joy. I would like to, if possible, find the car and have it restored as a gift to him. I'm not certain where to begin. The Vin number isn't the same as on the car search sites. Can anyone advise? Thanks for reading and have a great day!