I noticed these Märklin's are only filled halfway with water. (I add water until the overflow runs out.) But Mamods seem to be filled about 80% full. I don't run out of water on either for a fuel run, but it's a mmm...
I added more heat shielding from a vintage (early 1950s) Gilbert Erector set. The plates were the correct height and width for no trimming. Unlike Märklin or Mecanno plates, Gilbert are very bendable especially the odd aluminum one. (They had some aluminum parts post-war.) Notice the front of the burner area.