I know the things you mean - I wouldn't say rare - (I never do anyway) - not even scarce - although they're not that common either.
They are perfume bottles, very thick things which tend to overbalance sometimes. I've seen them in the blue with the yellowy streaky bits too. I think they're from around the '80s.
I'm not overly fond of them - they look too much like pws and I try to avoid both perfume bottles and pws.
I had a "strange" one of these for years before I realised it wasn't a pw, but a pb with the stopper stuck inside - so firmly stuck that somebody had ground the top of it off, just leaving the leftover bit stuck in the neck. :ho: