When you say "Old School Illusionist feel", I immediately think of the AD&D 1e Illusionist, which was a separate class from the wizard, complete with its own spell list (though there was, of course, some overlap with the wizard). And yeah, it does not have quite that feel. You could, you know, forgo selecting spells outside the flavor you desire, but this may involve gimping your character in some way, depending on what you desire for flavor as wizards are sometimes expected to have the right spell for the job, and balanced accordingly.
However, you mention Pathfinder, so maybe you mean 3.x specialist feel, which I would not refer to as "old school", but maybe I'm getting old. Personally, I think 5e's implementation of specialties is the best D&D has ever had, though I admit some of the abilities could use some redesign and balancing. I've never understood the call for a 'generalist' wizard, as wizards pretty much already are, with just some additional abilities in a specific area. As already mentioned, 5e has a lot of 'Arcane classes' that might be able to replicate the feel of a more narrow specialist, though none of them exactly replicate the illusionist of yesteryear. Lore Bard could make a good run at it, as well as Fey or GOO pack Warlock with the right invocations and boons. Even the Arcane Trickster might make a Mad Hatter feel with its focus on Illusion and Enchantment.
When I think about it, an Illusion/Trickery sub-class for the Sorcerer might be ideal, with access to more spells of that nature; but there is already quite a bit of 'blast' spells on to the Sorcerer spell list.
and used it for lack of a better term.
