I created a few patches for the Katana using some frequency response graphs I found online. I don't claim that these are exact copies of the sounds of these amps, but they do sound pretty good to my ear. The linked file contains four patches:
1) Clean (not trying to emulate anything here, just get a basic clean tone)
2) Brownface Vibroverb
3) AB763 min (treble and bass turned all the way down on the original circuit)
4) AB763 flat (treble and bass at 12 o'clock on the original circuit)
I put a graphic EQ before the pre-amp EQ, and left the pre-amp EQ flat so you can tweak the sound to taste, for room acoustics, guitars, etc. I like just a hint of breakup and saturation in my tone, so these might seem a little gainy and trebly if you don't roll back your guitar volume. On my Eastman AR371 with a P90 in the neck I roll the volume back until I hit the sweet spot for each patch, usually 8 or lower. The crunch channel seems to clean up magnificently in response to guitar volume and picking strength. When I created these, I was using the 0.5 watt setting with the master at 50%. Feel free to adjust master and gain to your liking. I've read that as the master volume is increased, the Katana will respond like a tube amp getting its tubes pushed harder.
I spent some time today trying to match my Katana to an amp based on the tweed Princeton at practice room levels. My Princeton-ish clone has a 10' Altec and an 8' Jensen, and my Katana has a WGS 12C/S. Accounting for differences in the cabs, I think I got pretty close. The guitar I used is a laminate fully-hollow with a P90 in the neck position. The gain on the Princeton clone is around 1 o'clock with the tone control wide open. (This clone uses a different tone stack than a real Princeton.) The tone should be rich in the midrange with a just the tiniest bit of breakup if you really hammer hard.
Here's the TSL file:
Dropbox - Tweed_Princeton_Clone.tsl
Dropbox - SneakyAmpsBlank.tsl