I know that this is your first post and you were instructed to make it here. However, your question is very specific about an expensive and out of production headphone. You're much more likely to get more and better responses by joining a thread about the SA5000, which you will most likely find in the Equipment Forums--Full Sized Headphone sub-section of the forum.
I you had a do-over, you should have made a short "Hi I'm 'Joe' from Taiwan and I like vintage Sony headphones" introductory post here. Immediately after that you should have made a substantive post (like the one you made here or something similar) in the part of forum I suggested above.