I've never had a headset problem either. The Stronglight V4 on my '74 PX10 is the only part I haven't replaced. I've never bought a bike that had a brinneled headset. I've replaced them only because they had wrench marks and exterior rust and because I stocked up on Stronglight A-9s when they were cheap.

I did try a VO cartridge bearing headset on my Raleigh and I like it very much. I wouldn't order one to replace a Hatta Vesta, though. A headset with a very short stack height is going to be required. I've been there and done that. The only thing I could find that would work is a Tange Levin. At least I think that's what it is. It has no markings.