i Bought that exact color bike but in my size they are fantastic bikes, i think better riders or at least as good as a professional, as a clean up and flip project id be all over it for $200, the group set alone is worth around that,
i wouldn't be concerned about that surface rust, British chrome from that era cleans up well, these are getting expensive in ride able condition even the frames on the bay go for $500 on up.
if you buying it to ride it you cant go wrong they are great.