Chris - Not sure what you are trying to document. Is it shell/body production date (Certificate of Origin - COO), vehicle donor date of manufacture (Title with matching chassis VIN), or the actual build or completion date? The CMC number you have is the fiberglass body number which matched a FL State issued COO --- an official document that looks like a car title and is issued by a bonded kit car producing entity like CMC or FF). When you go to a state DMV to first register your completed vehicle it takes this COO along with the donor car's title with chassis VIN to get a new title, registration and plates. All states vary in what they will register such a "mutt" as - i.e. year it replicates, year of VIN or engine date, date you register it - plus what they call it varies: Speedster-Replica, Specially Constructed Vehicle, VW, etc. Some states require a bill of sale and copies of receipts for all or major parts - so they can both prove it isn't stolen and to assess you taxes based on its value. Once registered the title becomes the important document (a bill of sale is also often required). So unless you bought yours as "vehicle parts" it should have come with the title signed by the transferring seller and a simple bill of sale (samples are all over the web - but it describes the car, mileage, selling cost, parties involved with dates, and often something like "sold as is/where is with no warrantees express or implied"
If you don't have a good title (PO may have kept it in his file cabinet) and can no longer get one --- find a wrecked VW that has a valid title and use its "chassis" under your body. This would probably be simplest in the long run.
