I don't think the old stuff is regarded as being that nice or good sounding. Seems like Kustom as a company are more known for the "tuck and roll" look than anything else, at least in the past.
James Brown, the guy who designed the Ultra Plus, 5150/6505, XXX, JSX and Classic series amps for Peavey is the main amp designer for Kustom now. I think his first designs were the Coupe series amps, and now the double cross...The cabs for those amps are pretty nice in terms of specs, Vintage 30 speakers, etc. So I think they are making an effort to become a little more known and respected. Seems like their bass amp line has been stepped up over the last few years, too. I see a decent amount of good looking bass rigs on stage with some nationals (Trivium comes to mind).