I found an original 1963 Ford Falcon Van brochure scanned in and posted on the internet (The Old Car Manual Project - Upload Gallery) that lists the curb weight of the Station Bus as 2830 lbs, the Club Wagon as 2930 lbs. and the Deluxe Club Wagon as 2970 lbs. plus 60 lbs. for each additional seat.
The brochure likewise says nothing about the Station Bus or the Club Wagon coming with any rear seats at all, but it does list the Deluxe Club Wagon as having 2 optional rear seats. So apparently, not even the Deluxe Club Wagon necessarily came with 2 rear seats.
Interestingly, the brochure lists the Deluxe Club Wagon as available only in Viking Blue.