MX5 Kaufberatung – Valve cover and pulley

Hello, I have decided to register here in the forum, maybe one of you can help me with a purchase decision. It is about an Mx5 Na from the year 1991, which is the first woman’s hand, summer and garage vehicle with 140k km. We have searched the typical rust spots all, the car is clean as regards rust. On one side the threshold was made new, this was also easy to see but also there without rust. We had now two points where We don’t know if these are safe. It starts with a damp spot on the valve lid. I have read the photo. I also read more often that you should pay attention to whether the strap disc has 4 or 8 holes and then still if this restlessness is running or eating. The disc now had 8 holes and we don’t know if you can count that as restless. We also attached the video to it once.