Thanks for the comments. I will plan to strip the frame and see if the oxidation has occurred in other places as well and if there are any cracks or other damages. With very nice I was more reflecting the geometry and the size of the frame, which is spot on for me and has been something I was looking for for some time to build a nice city bike. I don't think the quality or the construction of the frame is superb and I hoped the condition of the frame would have been better, but that's ok for me since I'm not planning to use it to make an MTB or road bike.