Chug, I don't think WW2 aircraft had de-icing other than Kilfrost paste which is like a brown grease to smear along leading edges and props. It was still available in the 1960s, a brave friend used it on his Cherokee in the airways. One thankfully brief but terrifying experience with freezing level 4000ft so plenty of room to descend and thaw out was enough for me and I still wonder how those who posted on this thread make so little reference to icing.