I'm pretty sure that I have that Hoppes in a cork top bottle.... and, I don't collect (it's just been in my cleaning kit for years....I even remember that I got it from a friend who was a pharmacist when he passed away at an early age MANY years ago....). I think it may still have liquid in it. Somehow, it's survived several household moves..!!! I also have several small bottles of Marvels oil patches... they, too, are still moist and seemingly viable. I imagine that if I were a collector, it might be frightening.
J.