Well for starters Navy blue was not a Fender color that year and to the best of my knowledge never has been.
There have been some that are similar though, for example, aged lake placid blue could be mistaken for navy blue.
The best course of action would be to either get it checked out by someone who knows vintage Fenders so that they can take it apart and verify authenticity or...
Another possible option is to post detailed photos here.
What we're looking for are,
Under the pickguard.
In the neck pocket.
The heel of the neck.
Pot codes.
Close ups of the soldering and wires.
Backs of pickups.
Full body shot. (front and back)
Headstock. (front and back)
Close up of the neck plate.
Now on the note of price,
if it really is an all original 72 p and it's in even rough condition it's worth well over 650
I'm sure someone will have a different opinion on this but I would be inclined to say,
if all original it could be worth anywhere between 1000 and 2500 depending on it's condition.
Best of luck,
Samantha.