Anything from the KotOR Era?
Not a chance.
Not only does the Executor have 4000 years worth of innovations to it, but the sheer size of the thing and the weapons batteries... Well, 5000 turbolasers is a lot of energy to direct onto a single target. Now, even assuming that only 20% of the shots hit -they're shooting like the Stormtroopers in the movies- that's 1000 bolts of energy, concentrated onto shields that are vastly outdated.
That's in a straight up 1 vs. 1 with both hypeing into the system at the same time.
However, if the Ebon Hawk or another like ship manages to get within the shields -much like in Solo Command when the pilot manages to get a TIE inside a SSD's shields and starts destroying it. Or if a pair of fighters manage to get in the superstructure of the Executor a la Wraith Squadron than the Executor is toast.
Likely? Less than a Snowball surviving in hell for a week. Possible? Yeah.
Now, let's even the odds, put in that fleet that was mentioned earlier.
Still, the Executor is going to win. Why? 4000 years of innovations and inventions and devices that were never even thought of in the KotOR era. So, asuming that they get the drop in on the Executor and pound it for a while, the Executor is going to win because it: A) Has 5000+ turbolasers to bear on anyship in the fleet. B) Huge TIE wing, including Bombers, Interceptor and Fighters. Even Defenders if you get lucky. And, C) It has powerful shields -unless the generator is destroyed and stray A-Wing hits the bridge... which, somehow, results in the ship's death... somehow. Never quite understood how.
Anyway, this question is like asking: "Can the Wright Flyer engage in Air to Air Combat with a F-22 Raptor and win?
Like hell it will. The F-22 will see it and destroy it before the Flyer even get's and idea where it is.
I imagine that much the same would occur when the Executor and a KotOR Era ship meet...
My 2 cents...