Thanks for the correction, guys, for some reason I thought Ampeg had been using Groove Tubes for the outputs. Beans-on-toast, true on the Winged C retail prices, but Ampeg doesn't buy parts at retail. So figure they're paying $150-170 tops for a set of Winged Cs.
The only other known improvement in the amps is purportedly the use of 1.6 mm (1/16") circuit boards and heaver copper traces on the boards. Yet, the boards in my Korean-made CL are the same thickness, and the copper on them is certainly thick enough to handle the currents involved. You can't get UL or CE approval if that's not the case. Then again, maybe Ampeg added 1/16" to the boards' thickness, and used heavier copper. That sure could not hurt.
I see the Heritage line as a piece of clever marketing on several levels by Ampeg. There's the "made in US" angle, the "better parts (at least tubes)" angle, and there's some vague intimation and hand-waving about QC, piece of mind, quality of components, etc. in the marketing material. IMO that's really what you're buying with the Heritage, something primarily of perception and psychology, which are the essence of good marketing.
Think about this for a second, though. Ampeg really can't say the Heritage line is that much better than the regular line, or they end up saying their regular line is crap. But they figure they can say so to the extent of roughly 40% higher street price and some soft additional marketing, and let the usual end user thinking fill in the blanks for them enough to sell some decent number of Heritage units.
Now mind you, I'm not saying it's not good to have a few extra jobs in the US these days, but these folks are really still doing final assembly and QC, and not full board stuffing and soldering (which would be automated anyway), or probably chassis and cabinet fabrication, either.