This is such a beauty , never smoked a real calabash it seem really satisfying!
For me personally the Calabash is the king of pipes ... for armchair movie watching no better pipe can there be.
If I was going to recommend a brand it would be Andreas Bauer.
If you're going to buy one I'd suggest an example from the 1980s with a meerschaum removable cup which can be replaced extending the life of the pipe by many years. I bought mine new at the time (this is my third replacement bowl) but similar examples can be found today in decent condition for under $100.
Best be careful with antique examples which mostly have sunken bowls as the bowl could be made of asbestos so if you're going in that direction it would be wise to try to get confirmation from the seller regarding the composition of the bowl.
Ours are not very similar that’s for sure. I honestly don’t know what a typical Prehistoric would look like. I imagine mine is pre 1980 as it has a metal rondel.
Here is what PIpedia says
Prehistoric -- England, unknown if also made in France: black sandblast. -TH: Available with Clear Persplex, Vulcanite, Pearl and Copper Acrylic -catalog (1976)
It seems there was quite a bit of variation?
Mine is also late 1970s with the metal roundel so, yes, looks like 'Prehistoric' was just another name for rustic ... I guess it's possible that prehistorics made in/for the UK looked like mine with the smooth rounded bowl lip and those destined for other territories looked less prehistoric and more black shell/rustic/sandblast ?