Noun - a subcategory of hipster (usually an early twenty-something) who melds characteristics of the chicster (fashionable clothing, etc.) with anachronistic idioms.
The old-soulster employs outdated phraseology in their everyday vocabularly; words such as swell or indeed are top-notch for the old-soulster.
S/he also finds delight in age-inappropriate activities, such as antiquing, collecting art glass or discussing the latest issue of the New Yorker with a fellow old-soulster.
The old-soulster drives an old car, usually an Austin-Healey or other British sports car, writes their term papers on a typewriter, and definitely smokes a pipe whenever possible.
Their music is drastically disparate form that of the hipster and many of the other subcategories. While other hipsters blast indie rock, the old-soulster is quite content blowing out the sound system of their British car with the minimalist stylings of Philip Glass.
For the old-soulster, irony is best expressed by the juxtaposition of old and new. The use of their iPad for perusing Tumblr while listening to their vinyl copy of Einstein on the Beach on a nearby record player is a prime example.
One would most likely find this hipster socializing in a coffee house, surrounded by other hipsters, and is clearly identified by a bow tie, wool/tweed clothing and standard hipster eyewear, extremely fashionable footwear and bag, probably accompanied by a copy of an eighteenth century novel or the latest New York Times.
Dude I: Hey... look over there! Check out that guy's bow tie... what's his deal??
Dude II: I think he's an old-soulster...
Dude I: Oh. Makes sense, I guess.
Dude II: No, not really.