Ok, so I finally returned from evacuation in Santa Rosa and had time to listen on my studio monitors to the original past.
What I hear is twofold. Firstly the cab that profile is using is horrrrrrrrrible, like literally it's an ice pick in my ears, are you sure the cab output is even enabled? Because this sounds like utter utter shite, like I couldn't even believe my ears how horrible this sounded. It sounded as bad as IR's, which to me sound pretty much like someone is using a cheap EQ on a DI. Find a good cab, maybe one from the VSP pack, because whomever did that knew what actual amps sound like and hasn't been poisoned by the 90's Mesa Rectumfryer sound and years of ear atrophy from Trotsky's favorite guitar sim - the Pod.
The second thing, and this is a big one - room sound. The original has lots of that small guitar room verb going on. You cannot achieve that through EQ... sorry, it just cannot be done, doesn't matter how much you might want it to be true, doesn't matter how much Kemper might want it to be true either. So if you crank up the space parameter you'll get closer, it'll sound almost like you've plugged your amp in a public latrine stall, so I suggest instead using a reverb with lots of damping... looots of damping. You got that? I mean we're talking felt walls here, damp that motherfucker all the way! You're not paying attention, I said damp it! Good. Now dial it back to be tasteful.
After that it's up to you, double track that bad boy. So far in my experience with the Kemper if you're after a specific tone it's sometimes no faster than just micing a real amp, it really is shit in shit out, gold in gold out. Start with the very best stuff you can find or profile your own amp. That r_u_sirius profile further up is better, but still needs the room and a little tweaking in the cab section.
Best of luck, honestly I think the biggest problem for me when it comes to any vintage tone (which is most of what I'm into) is the fact that the Kemper only emulates a close mic'd tone. Getting that room back in there is critical IMO.
Once I retrieve my guitars from storage I'll see about giving it a shot.