Agree, there are many variations of "Tork Thrust" American wheels. "Backspacing" might be more understood, as to terminology, than "offset". Although I always liked the "offset" orientation, but in reality, the backspacing of the wheels is more important as to fit. Offset is important as to wheel bearing loads and such. The same style of wheel can vary as to rim diameter, wheel width, bolt pattern (5x4.5" in this case).
DO YOUR due diligence before purchasing something that LOOKS like it can fit that DOES NOT fit!
A P215 tire will not have enough weight capacity for a 5000 lb C-body wagon PLUS people (figure 200lbs each) in it, any additional luggage (up to 500lbs), and a full tank (5.7 lbs/gallon x 23 gallons)) of gas, generally. Unless you want to run the tires at 50+psi all of the time.
Main thing is to determine the backspacing of the wheels, then get the tires with enough weight capacity at 35psi for them. 7" rim with a 4.0-4.25" backspacing usually works.
Considering that OEM size was P235/75x15, those pictured tires will make the speedometer and odometer indicate "faster" than actual road speed/distance as they will be making more revolutions/miles than the OEM size tires do.
Just some thoughts,
CBODY67