Classic/Antique Car Repair: Transmission dipstick/tube, dipstick tube, mustang coupe

Question
My son bought himself a 69 Mustang Coupe (302 motor) without checking anything, and now he's paying for it.  A hose came loose from the transmission to the radiator/cooler and blew fluid all over the place.  He replaced the hose and was getting ready to add fluid, but first check the fluid level.  He pulls what he thinks is the transmission dipstick, BUT NO DIPSTICK comes out with the cap.  Either NO dipstick to begin with, or it has broken off in the tube.  Do we need to drop the transmission to remove the tube, or is there another remedy?

Answer
The dipstick can't go into the transmission and hurt anything - if it doesn't come out with the cap, it is plain just missing, or perhaps just broken off and sitting down in the tube.   Take a flashlight to see if you can see the broken off end - it won't have slipped down very far.  It can just stay there, but you'll need to get another dipstick from a parts dealer - you'll need to know which transmission is in the car.   

To keep driving the car in the meantime, if you can estimate how much fluid was lost, and add that - if the transmission acts OK, without making any strange noises, it is probably OK to drive that way.

Dick