Maybe that is the "Power Flow Ventilation" (sales speak for rear defog)?

I don't see rear defrost on the order form/invoice, Power Flow option would have a switch...

That's probably the most logical conclusion. Seeing as how the salesman wrote "Tudor" in place of "Two Door" or "2 Dr", he may have had his own terminology for a rear defog also :dunno:

Wow, that thing is gonna need a whole lotta love to return from the dead.

Tudor was common language on the Certificate of Title back in the day,just like Coupe and Cabriolet is.
Some states have dropped this language and some still use it.
It started as a marketing ploy.Manufacturers had pet names for different body styles. The model T touring car became a phaeton on the model A.It sounded better.The tudor and fordor were marketing terms designed to stick in the minds of the public.Some manufacturers called the 2 door a coach.Closed cars were called sedans,and still are. The terms phaeton,sedan,coach etc. are from the horse drawn era,which was still in the memory of many buyers.Tudor and fordor are a step removed from those horse & buggy days.Both of my 1970 Missouri cars still have "Tudor" printed on their title descriptions.

power flow ventilation was an option for no ac cars. it had fans that pulled air thru the kick panels and exited it thru the cowl section. I used to wonder why they did it that way and I talked to a retired engineer at a car show and he explained that it had to blow it out the cowl or it would have created a problem with clogging up with leaves and other debris. makes sense. I have a 69 ra 4 gto that has it. fairly rare option. it used a switch on the dash to operate it.

Gto...
 

Foam band around the paper filter.