Was it 14" or 15"?
Yes.
That is the simple answer, since no other wheel sizes were available.
If you do not know for sure what it came with, check & see if;
1. The original door jamb tire sticker is present.
2. What position is your spare tire stud in the trunk, forward or back?
3. Is there any evidence of red paint on your rear drums?
4. What is the axle ratio & speedometeer gear color / number?
With that data you can make a fairly educated guess it the car has not been messed with.
Of course, if you have a broadcast sheet for it, then it eliminates the guesswork.