Are you missing the original entirely? Nothing on the driver's front kick-panel at all?
Yours would not have had a door tag, but their sheet says that just as a generic description I would think.
Since you have the transmission, color and DSO, does that mean you do have the original tag?
Kind of surprised they're willing to do a '66 since they don't have the original paperwork for them. But I guess if you have all the info and can prove it, they can make one from the same blanks they use for later years.
Check with Okie here about the date, since that's built into the VIN itself.
The Warranty number I've never heard of. But since the warranty plate (which is the VIN tag on our vehicles) uses the VIN as the identifier, maybe that's what they mean?
If so then you have your number. Just need those last couple of data points to be complete.
Sometimes a string of two or more letters indicates multiple things, but I see only single digit indications in what you posted. Stuff like two letters together could mean it's got a half cab AND a bench seat. Or 4.11 gears AND a passenger seat. Stuff like that.
Good luck. Hopefully Okie will see this and can help you out.
Paul