I had the opportunity to go with others to a bronze foundry the other day in the Docklands area of London. The above video gives you a good idea of the process, although it is another foundry. We went to Bronze Age. They weren't pouring that day so we missed the most exciting bit but it was fascinating.
Bonhoeffer uses a similar phrase 'worldly Christianity'. It's J Gresham Machen that I want to line up most closely with. See his Christianity and culture here. Having done commentaries on Proverbs (Heavenly Wisdom) and Song of Songs (Heavenly Love), a matching title for Ecclesiastes would be Heavenly Worldliness. For my stance on worldliness, see 3 posts here.