Separately I want to address the "China" issue some people seem to throw out - not specifically calling anyone out.
The Vibrant 12810 IC is made in China
The Majesty IC is made in China
Likely every core on the market, save Wagner and maybe some other tube and fin models, are in fact made in China.
The manufacturing country does not matter, the quality of the part and factory it comes from matters. China is, for many things, the best in the world as hard goods manufacturing outside of the ultra high end. Also note that for many manufacturing processes China is the only country that actually does this stuff. Bar and plate IC core and end tank casting appears to be one of those categories.
Tube and fin radiator manufacturing has a long history in Britain - so you do still see some of that done there, its more of a skilled trade than a scaled manufacturing process.
Some of my knowledge may be a bit outdated, I knew more first hand stuff about this a decade ago.