[Bernhard]

I know this not a direct answer to you question.
But the key to good tire fitment is mock up.
The car can have more clearance on one side than the other because the frame is slightly shifted to on side or the other. This can occur for multiple of reasons and may have come straight from the factory this way.
We would move the rim inward by increasing the back spacing . You do not have to shorten the diff just increase back spacing.
I would start with moving the rim inward as far as you can go with out having tire rubbing issues.
Mock-up is key to good tire fitment. We would use inexpensive steel rims during mock up.
I would go with a 15" tire & rim, they fill the wheel well better and adds to the joy of driving by providing superior performance.
All tires have slightly different profiles / bulge so it good to know the tire you want to run.