One thing I noticed on my pretty much the same fintail many years ago. It seemed very sensitive to the type of tires on it. It could and would understeer until I got the right tires. Otherwise I could not fault the car.

These cars where ahead of the competition in many ways back then. I also considered it a very well built car.

Although be sure to check the valve clearances as per the maintenance requirement. Back then the adjusters sometimes moved a little it seemed. Otherwise You can burn an exhaust valve.

The adjusters later where made a much heavier interference thread fit. You should be able to get a original offset forked valve adjustment wrench easy and cheap enough still.